egre 427 advanced digital design introduction to microcontrollers application-specific integrated...

EGRE 427 Advanced Digital Design

Introduction to Microcontrollers

Application-Specific Integrated CircuitsMichael John Sebastian SmithAddison Wesley, 1997


CPU MemorySystem

Input/OutputSystem

Components of a Computer System


Microcontrollers Microcontrollers integrate all the components of a computer system onto a

single chip All components are optimized to perform the functions necessary to control a

larger system Size, capability, cost, and power consumption are more important

considerations 8 bit microcontrollers have the majority of the market right now, but 16 and 32

bit microcontrollers are available and gaining market share

CPUCore

ROM Memory

RAM Memory

I/O

Sys

tem

MicrocontollerChip


Microcontroller Components

CPU May be an adaptation of an existing microprocessor or a completely

new architecture Instruction set is typically modified to deal with new I/O system

Memory On-chip NVRM to hold program - can be mask programmable ROM,

OTP ROM, or EPROM/EEPROM On-chip RAM for variable storage - usually small amount and can

double as P’s registers Both can be expanded using off-chip memory (extended microcontroller

mode)


Microcontroller Components (cont.)

I/O system - tailored to provide services usually required in embedded control applications

Binary I/O pins (buffered, built-in pull ups, etc.) Timers/Counters Pulse Width Modulation (PWM) outputs Capture inputs AD and DA converters UART or other communication controllers

Miscellaneous Oscillator options Reset options Sleep/reduced power modes External interrupts Watchdog timers


Microcontroller Binary I/O pins

Binary I/O pins are pins that can either write (output) a ‘1’ (Vdd) or ‘0’ (Gnd) value, or read (input) a ‘1’ or ‘0’ value

Direction (input or output) is typically set on a per bit basis with a direction bit

These type of I/Os are often multiplexed with other I/O functions

Pull up (or pull down) resistors are typically included for connection to a bus

Drive capability is usually in the medium range (20 mA - 60 mA)

Interrupt on change features are sometimes included


Microcontroller Counter/Timers

Timers are special registers within the microcontroller that are configured as binary counters

Timer registers can be preloaded with a starting value and possibly have an ending value (other than overflow) specified

Overflow or hitting the end value generates an interrupt to the processor

Timer register clocking: Internal CPU clock - timer mode External clock via a dedicated I/O pin - counter mode

Timers are the basis for PWM outputs and Capture inputs Timers are also sometimes used by the external communications

functions (UARTS, etc.)


Microcontroller PWM Outputs

Pulse Width Modulation (PWM) outputs are special purpose outputs that can generate a specified train of pulses

Internal general purpose timer registers are often used to generate the pulse train

When generating a PWM output, timers can not be used for other purposes

Typically the period and duty cycle of the pulse train are specified Period is specified in counting units of the specified timer Duty cycle is specified as the actual width (in timer units) of the “on”

pulse

Period

DutyCycle


Microcontroller Capture Inputs

Capture inputs are used to count external events

A general purpose timer is associated with each capture register

The timer is incremented each time the external event occurs

The external event can be a rising or falling edge on the capture input, or multiples there of (i.e., every 4th rising/falling edge, every 16th rising/falling edge)

The capture (timer) register value can be read or an interrupt can be generated when it equals a specified value


Other Microcontroller I/O functions

Some microcontrollers include an internal Analog-to-Digital converter (some with multiple channels)

Conversion values are placed in a special purpose register Conversion is started under software control Accuracy (no. of bits) is variable, but is typically in the 8-16 bit range Input voltage usually in the range of 0 to 2X or 3X Vdd

Digital-to-Analog converters are also sometimes provided Input is typically one or two processor data words wide Output is 0 to 2X or 3X Vdd Current drive is equivalent to other I/O ports


Other Microcontroller I/O functions (etc.)

Most microcontrollers include built-in serial communications capabilities

Universal Asynchronous Receiver/Transmitter (UART) Serial Peripheral Interface (SPI) Microwire

I2C

Most microcontrollers also include the following capabilities for dealing with real-time systems:

Optional oscillator sources such as external clock, external crystal, or simple RC timing circuit

Watchdog timers that will interrupt the CPU after a certain period of time if the CPU does not reset it - useful for recovering from software malfunctions

Power-down or sleep modes from which wake-up occurs on interrupts (from watchdog timer, timer/counters, capture inputs, external interrupts, etc.)


Microchip PIC17C4X Series Microcontrollers

Harvard architecture - 16 bit instructions, 8 bit data

RISC instruction set - 58 total instructions

Single cycle (4 clock cycles) instruction execution except for program branches and table operation which require 2 cycles

DC (0Hz) to 33 MHz clock input - DC to 121ns instruction cycle time

Hardware multiplier (except PIC17C42

40 pin DIP package

EPROM 2K, 4K, and 8K X 16 options External program memory up to 64K X 16 can be used (requires the

elimination of 16 I/O pins) UV EPROM OTP Manufacturer Programmed

Data RAM 232 or 454 bytes available


Microchip PIC17C4X Series Microcontrollers (cont.)

33 I/O pins with individual direction control

Two capture inputs and two PWM outputs

Two 16 bit and two 8 bit timers

Universal Synchronous/Asynchronous Receiver/Transmitter (USART)

SPI Microwire I2C

Power-on Reset, Power-up and Oscillator Start-up Timers

Watchdog timer

Sleep mode

Selectable oscillator options


PIC17C4X Pinout


PIC17C4X I/O Functions


PIC17C4X I/O Functions (cont.)


PIC17C4X Architecture


PIC17C4X Instruction Timing


PIC17C4X Instruction Formats


PIC17C4X Opcode Fields


PIC17C4X Instructions


PIC17C4X Instructions (cont.)


PIC17C4X Memory Organization


PIC17C4X Memory Modes

4 available modes of operation:

Microprocessor Microcontroller Extended Microcontroller Protected Microcontroller

Microcontroller and protected microcontoller modes only allow internal execution

Protected microcontroller model also enables code protection feature

Extended microcontroller mode accesses both internal and external program memory

Microprocessor mode only accesses external program memory


Interfacing the PIC17C4X to External Program Memory


Interfacing the PIC17C4X to External Program Memory (cont.)


PIC17C4X Register File (Data Memory) Map


PIC17C4X Special Function Registers


PIC17C4X Special Function Registers (cont.)


PIC17C4X Interrupts PIC17C4X microcontrollers can have 11 sources of interrupts:

External interrupt via RA0/INT pin Change on RB7:RB0 pins TMR0 Overflow TMR1 Overflow TMR2 Overflow TMR3 Overflow

There are 4 interrupt vectors corresponding to these 4 interrupt sources:

External interrupt via RA0/INT pin TMR0 Overflow T0CKI edge occurred Any peripheral interrupt (i.e., everything else)

Individual interrupt flags for the first 3 are cleared when the interrupt vector is executed

USART Transmit buffer empty USART Receive buffer full Capture 1 Capture 2 T0CKI edge occurred


PIC17C4X Interrupts (cont.)

Peripheral interrupt flags are not automatically cleared to allow testing for which type of interrupt occurred

These flags must be cleared in software to avoid infinite interrupt loops Only the PC is automatically saved on the stack when the interrupt

occurs, all other registers used must be explicitly saved in the ISR There are 4 registers used in control and status of interrupts:

CPUSTA INTSTA PIE PIR

CPUSTA register contains the Global Interrupt Disable (GLINTD) bit When GLINTD is set, interrupts are disabled GLINTD is automatically set whenever an interrupt is responded to


PIC17C4X Interrupt Logic


PIC17C4X Interrupt Status Register (INSTA)

The INSTA contains the individual flag (interrupt request) bits and the individual interrupt enable bits for the four major types of interrupts

If a peripheral interrupt occurred, the PIR register must be examined to determine the requesting peripheral


PIC17C4X Peripheral Interrupt Enable Register (PIE)

The PIE register contains the individual interrupt enable bits for the peripherals


PIC17C4X Peripheral Interrupt Request Register (PIR)

The PIR register contains the individual flag (interrupt request) bits for the peripherals


PIC17C4X I/O Ports

PIC17C4X micrcontollers have five I/O ports - PORTA through PORTE

PORTB through PORTE have a corresponding Data Direction Register (DDRX) to configure pins as either inputs or outputs

PORTC, PORTD, and PORTE pins are multiplexed with the system bus - these ports are not available in the microprocessor or extended microcontroller modes

PORTA and PORTB are multiplexed with the peripheral features of the microcontroller

Timer modules Capture module PWM module USART module External interrupt pins

The PWM and USART modules automatically configure their I/O pins - the other modules must have their DDR bits configured appropriately


PIC17C4X PORTA

PORTA does not have a DDR

RA0/INT is either a data input or external interrupt input

RA1/T0CKI is either a data input, the TMR0 external clock, or an external interrupt input

RA2, RA3 are open drain outputs - simply write to PORTA register to output values to them, the other PORTA pins are unaffected

RA4, RA5 are either inputs or USART pins - they are automatically configured by the USART module if it is active

Bit 7 of the PORTA register controls the weak pull-up resistors for PORTB


PIC17C4X PORTA (cont.)


PIC17C4X PORTB

PORTB is an 8-bit wide bi-directional port The corresponding data direction register is DDRB

A ‘1’ in the bit of DDRB configures the pin as an input A ‘0’ in the bit of DDRB configures the pin as an output

Reading PORTB reads the status of the pins - writing PORTB writes to the port latch

Each pin of PORTB has a weak internal pull-up resistor enabled by clearing RBPU

The weak pull-ups are enabled on reset and automatically turned off when a pin is configured as an output

PORTB has an interrupt on change feature Only pins configured as inputs cause this interrupt to occur Input values are compared with the value in the PORTB data latch - any

mismatch causes the interrupt This interrupt can wake the processor from the SLEEP mode


PIC17C4X PORTB (cont.)


PIC17C4X PORTC

PORTC is an 8-bit wide bi-directional port

The corresponding data direction register is DDRC A ‘1’ in the bit of DDRC configures the pin as an input A ‘0’ in the bit of DDRC configures the pin as an output

Reading PORTC reads the status of the pins - writing PORTC writes to the port latch

In the microprocessor or extended microcontroller mode, this port is the low order byte of the system bus (AD7:AD0) and is unavailable as an I/O port


PIC17C4X PORTC (cont.)


PIC17C4X PORTD

PORTD is an 8-bit wide bi-directional port

The corresponding data direction register is DDRD A ‘1’ in the bit of DDRD configures the pin as an input A ‘0’ in the bit of DDRD configures the pin as an output

Reading PORTD reads the status of the pins - writing PORTD writes to the port latch

In the microprocessor or extended microcontroller mode, this port is the high order byte of the system bus (AD15:AD8) and is unavailable as an I/O port


PIC17C4X PORTD (cont.)


PIC17C4X PORTE

PORTE is an 3-bit wide bi-directional port

The corresponding data direction register is DDRE A ‘1’ in the bit of DDRE configures the pin as an input A ‘0’ in the bit of DDRE configures the pin as an output

Reading PORTE reads the status of the pins - writing PORTE writes to the port latch

In the microprocessor or extended microcontroller mode, this port contains the control bits for the system bus (Address Latch Enable ALE, Output Enable OE, and Write WR) and is unavailable as an I/O port


PIC17C4X PORTE (cont.)


PIC17C4X Timer Resources

The PIC17C4x microcontroller has four timer modules Timer0 - 16-bit timer with programmable 8-bit prescaler Timer1 - 8-bit timer Timer2 - 8-bit timer Timer3 - 16-bit timer

Each timer module can generate an interrupt (although they are different types of interrupts for the different timers)

The Pulse Width Modulation (PWM) outputs use the TMR1 and TMR2 timers and the Capture inputs use the TMR3 timer


PIC17C4X Timer0

The Timer0 module contains a 16-bit timer/counter The high byte of the timer is TMR0H and the low byte is TMR0L The Timer0 module includes an 8-bit programmable prescaler that

makes it an effective 24 bit overflow timer The clock source is programmable to be either the internal

instruction clock (timer) or the RA1/T0CKI pin (counter) The external edge that the time increments on can be selected in

software When the timer rolls over from FFFFh to 0000h, the TMR0 Interrupt

Flag bit (T0IF) is set and the processor vectors to the TMR0 interrupt vector - the T0IF bit is automatically cleared

The prescaler output (input to the timer) is synchronized with the internal clock

The timer high and low bytes can be written and read in software Care must be taken to ensure that the value doesn’t roll over during the

operation


PIC17C4X Timer0 (cont.)


PIC17C4X Timer1, Timer2, and Timer3

Timer1 and Timer2 are two 8-bit timer/counters (TMR1 and TMR2) with an associated period register (PR1 and PR2)

Both timers can either increment on the internal clock or on the falling edge of the external clock on pin RB4/TCKL12

Timer1 and Timer2 can also be configured to operate as a single 16-bit timer

Timer1 and Timer2 are the time base for the PWM outputs Timer3 is a 16-bit timer/counter consisting of the TMR3H and

TMR3L bytes Timer3 can increment from the internal clock or the RB5/TCLK3 pin Timer3 is the time base for the two 16 bit captures Two registers (PR3H/CA1H:PR3L/CA1L) are used as a 16-bit

period register or a 16-bit Capture1 register Two registers (CA2H:CA2L) are strictly the Capture2 registers


PIC17C4X Timer1 and Timer2

Timer1 and Timer2 operate in 8-bit mode when the T16 bit is clear Their clocks can be independently selected to be either internal or an

external falling edge (RB4/TCLK12) The timers increment from 00h until they equal the period register

(PRx) and then reset in the next cycle The timer interrupt flag (TMR1F and TMR2F flag is set when the timer

rolls over (and their individual interrupts are enabled) The Timer1 and Timer2 interrupts are peripheral interrupts

Peripheral interrupts as well as the individual timer interrupts must be enabled

The PIR register must be checked to determine the source of interrupts The individual timer interrupt flags must be cleared in software

When the T16 bit is set Timer1 and Timer2 form a 16-bit timer/counter The timer counts from 0000h until it equals the period register

(PR2:PR1) The TMR1CS bit controls the clock source for the 16-bit timer


PIC17C4X Timer1 and Timer2 (cont.)


PIC17C4X PWM Outputs

Two high-speed Pulse Width Modulation (PWM) outputs are provided (RB2/PWM1 and RB3/PWM2)PWM1 uses Timer1 as its time-base while PWM2 can be configured to use either Timer1 or TImer2 as its time-baseEach PWM output has a maximum resolution of 10-bits (with the addition of 2-bit internal Q clock or 2 bits of the prescaler)The PWM1ON and PWM2ON bits enable the PWM outputs and the corresponding DDRB bits are ignoredThe PWM periods are determined by the PR1 and PR2 registers:

period of PWM1 = [(PR1) + 1] x 4Tosc

period of PWM2 = [(PR2) + 1] x 4Tosc


PIC17C4X PWM Outputs (cont.)

The duty cycle is determined by the 10-bit value DCx<9:0> where DCx<9:2>=PWxDCH<7:0> and DCx<1:0>=PWxDCL<7:6>

PWMx Duty Cycle = (DCx) x Tosc

If DCx=0 then the duty cycle is zero, if PRx=PWxDCH then the PWM output will be low for one to four Q-clocks depending on PWxDCL<7:6>

For a 100% duty cycle, PWxDCH must be greater than the PRx value

The Timer1 and Timer2 interrupts can be enabled when using them for a PWM time-base - allows the user to write a new duty cycle value before the timer roll-over

Using the external clock for the time-base of the PWM outputs can cause jitter in the duty cycle and period due to the synchronization with the internal Q clock


PIC17C4X PWM Outputs (cont.)


PIC17C4X Timer3

Timer3 is a 16-bit timer/counter consisting of the TMR3H and TMR3L bytes

When the TMR3CS bit is clear, the timer increments every instruction cycle - when it is clear, it increments every falling edge of the RB5/TCKL3 pin

The TMR3ON bit must be set of the timer to increment Timer3 has two modes of operation depending on the CA1/PR3 bit:

One capture and one period register Dual capture register mode

The 16-bit capture registers capture the value of Timer3 when events are detected on the capture pins (RB0/CAP1 and RB1/CAP2)

An event can be: a rising edge a falling edge every 4th rising edge every 16th rising edge


PIC17C4X One Capture and One Period Register Mode

This mode is selected if the CA1/PR3 bit is clear The PR3H/CA1H and PR3L/CA1L registers form a 16-bit period

register for Timer3 - Timer3 increments from 0000h to the value in the period register and then rolls over

The CA2ED1 and CA2ED0 bits determine the event on which capture will be made:

capture on every falling edge (00) capture on every rising edge (01) capture on every 4th rising edge (10) capture on every 16th rising edge (11)

On a capture event, the value of TMR3H/TMR3L will be copied into the CA2H/CA2L register and the CA2IF interrupt bit is set (if enabled with CA2IE)

A capture overflow bit CA2OVF value of ‘1’ indicates that the value in the capture register had not been read before the next capture event occurred

The new value of TMR3 is not copied into the capture register and the overflow flag is not set until the value in the capture register is read


PIC17C4X One Capture and One Period Register Mode (cont.)


PIC17C4X Dual Capture Register Mode

This mode is selected if the CA1/PR3 bit is set TMR3 runs without a period register and increments from 0000h to

FFFFh and then rolls over - an interrupt (TMR3IF) can be generated on this roll over

The two 16-bit capture registers are PR3H/CA1H/PR3H/CA1L and CA2H/CA2L

Capture modes are separately configured by the CA1ED1, CA1ED0 and CA2ED1 and CA2ED0 bits

Interrupts are separately enabled (CA1IE and CA2IE) and flagged (CA1IF and CA2IF)

Likewise, overflow is separately indicated (CA1OVF and CA2OVF)


PIC17C4X Dual Capture Register Mode(cont.)


PIC17C4X Capture Inputs (cont.)


PIC17C4X Universal Synchronous Asynchronous Receiver Transmitter (USART)

USART is a serial I/O module that can be configured as a full duplex asynchronous system or a half duplex synchronous system

The USART has the following modes: Asynchronous (full duplex) Synchronous - Master (half duplex) Synchronous - Slave (half duplex)

The USART can communicate using a number of different protocols:

RS232 SPI Microwire I2C


PIC17C4X USART


PIC17C4X USART (cont.)


PIC17C4X Special Features

Like all microcontrollers, the PIC17C4X includes several additional special features to deal with the needs of real-time embedded applications:

Oscillator type selection - RC oscillator saves system cost while the LF crystal option saves power

Various Reset utilities Power-on Reset - processor automatically resets on power-up Power-up timer - provides a fixed 96 ms delay on power-up to allow power

supply to stabilize Oscillator Start-up timer - keeps the chip in reset until the oscillator stabilizes

Interrupts Watchdog Timer Sleep mode - low current power-down mode, user can wake through

external reset, watchdog timer reset or an interrupt Code protection


PIC17C4X Oscillator Configurations


PIC17C4X Oscillator Configurations (cont.)


PIC17C4X Watchdog Timer

The Watchdog Timer’s (WDT) function is to recover from software malfunctions

Uses an internal free-running RC oscillator as its clock source The WDT can only be turned off via EPROM bits The WDT has a nominal time-out period of 12 ms - if longer time-

outs are desired, a prescaler with a division ratio of up to 1:256 can be assigned to the WDT thus realizing time-out periods of up to 3 seconds

The CLRWDT and SLEEP instructions clear the WDT A WDT time-out generates a reset condition Software must check to see if the reset was due to a WDT time-out

by checking the TO bit in the CPU status register


PIC17C4X Watchdog Timer


PIC17C4X Sleep (Power-down) Mode

Sleep mode is entered by executing a SLEEP instruction In Sleep mode, the oscillator driver is turned off and the I/O ports

maintain their driven value (high, low or high-impedance) The microcontroller can wake from Sleep mode through one of the

following events: A Power-on Reset External reset on the MCLR/Vpp pin WDT Reset (if WDT was enabled) Interrupt from RA0/INT pin, RB post change, T0CKI interrupt, or some

peripheral interrupts Capture 1 interrupt Capture2 interrupt USART synchronous slave transmit interrupt USART synchronous slave receive interrupt

Other peripherals can not wake from Sleep because during Sleep, no on-chip Q clocks are present


Programming the PIC17C4X in “C”

The Microchip development environment includes a compiler for the “C” programming language

Included with the compiler a libraries for manipulating the special functions of the PIC microcontrollers

These libraries consist of header files which define the registers and variables necessary and C functions which perform some of the needed actions

The main header file for each processor defines the all of the registers and individual bits that have been discussed - thus it is always possible for you to manipulate the hardware registers and setup the functions directly


P17c44.h#pragma nolist/*---------------------------------------------------------- * MPLAB-C17 v2.10 PIC17C44 processor header * * (c) Copyright Microchip Technology, All rights reserved *---------------------------------------------------------*/#ifndef __17C44_H#define __17C44_H extern near unsigned char INDF0;extern near unsigned char FSR0;extern volatile near unsigned char PCL;extern near unsigned char PCLATH;extern volatile near unsigned char ALUSTA;extern volatile near struct { unsigned C:1; unsigned DC:1; unsigned Z:1; unsigned OV:1; unsigned FS0:1; unsigned FS1:1; unsigned FS2:1; unsigned FS3:1;} ALUSTAbits ;extern near unsigned char T0STA;extern near struct { unsigned :1; unsigned T0PS0:1; unsigned T0PS1:1; unsigned T0PS2:1; unsigned T0PS3:1; unsigned T0CS:1; unsigned T0SE:1; unsigned INTEDG:1;} T0STAbits ;

extern volatile near unsigned char CPUSTA;extern volatile near struct { unsigned NOT_BOR:1; unsigned NOT_POR:1; unsigned NOT_PD:1; unsigned NOT_TO:1; unsigned GLINTD:1; unsigned STKAV:1;} CPUSTAbits ;extern volatile near unsigned char INTSTA;extern volatile near struct { unsigned INTE:1; unsigned T0IE:1; unsigned T0CKIE:1; unsigned PEIE:1; unsigned INTF:1; unsigned T0IF:1; unsigned T0CKIF:1; unsigned PEIF:1;} INTSTAbits ;extern near unsigned char INDF1;extern near unsigned char FSR1;extern near unsigned char WREG;extern volatile near unsigned TMR0;extern volatile near unsigned char TMR0L;extern volatile near unsigned char TMR0H;extern near unsigned TBLPTR;extern near unsigned char TBLPTRL;extern near unsigned char TBLPTRH;extern near unsigned char BSR;extern volatile far unsigned char PORTA;


P17c44.h (cont.)extern volatile far union { struct { unsigned RA0:1; unsigned RA1:1; unsigned RA2:1; unsigned RA3:1; unsigned RA4:1; unsigned RA5:1; unsigned :1; unsigned NOT_RBPU:1; } ; struct { unsigned INT:1; unsigned T0CKI:1; } ;} PORTAbits ;extern far unsigned char DDRB;extern far struct { unsigned RB0:1; unsigned RB1:1; unsigned RB2:1; unsigned RB3:1; unsigned RB4:1; unsigned RB5:1; unsigned RB6:1; unsigned RB7:1;} DDRBbits ;extern volatile far unsigned char PORTB;extern volatile far struct { unsigned RB0:1; unsigned RB1:1; unsigned RB2:1; unsigned RB3:1; unsigned RB4:1; unsigned RB5:1; unsigned RB6:1; unsigned RB7:1;} PORTBbits ;

extern far unsigned char RCSTA;extern far struct { unsigned RX9D:1; unsigned OERR:1; unsigned FERR:1; unsigned :1; unsigned CREN:1; unsigned SREN:1; unsigned RX9:1; unsigned SPEN:1;} RCSTAbits ;extern far unsigned char RCREG;extern far unsigned char TXSTA;extern far struct { unsigned TX9D:1; unsigned TRMT:1; unsigned :2; unsigned SYNC:1; unsigned TXEN:1; unsigned TX9:1; unsigned CSRC:1;} TXSTAbits ;extern far unsigned char TXREG;extern far unsigned char SPBRG;extern near unsigned PROD;extern near unsigned char PRODL;extern near unsigned char PRODH;extern far unsigned char DDRC;extern far struct { unsigned RC0:1; unsigned RC1:1; unsigned RC2:1; unsigned RC3:1; unsigned RC4:1; unsigned RC5:1; unsigned RC6:1; unsigned RC7:1;} DDRCbits ;extern volatile far unsigned char PORTC;


P17c44.h (cont.)extern volatile far union { struct { unsigned RD0:1; unsigned RD1:1; unsigned RD2:1; unsigned RD3:1; unsigned RD4:1; unsigned RD5:1; unsigned RD6:1; unsigned RD7:1; } ; struct { unsigned AD8:1; unsigned AD9:1; unsigned AD10:1; unsigned AD11:1; unsigned AD12:1; unsigned AD13:1; unsigned AD14:1; unsigned AD15:1; } ;} PORTDbits ;extern far unsigned char DDRE;extern far struct { unsigned RE0:1; unsigned RE1:1; unsigned RE2:1;} DDREbits ;extern volatile far unsigned char PORTE;extern volatile far union { struct { unsigned ALE:1; unsigned NOT_OE:1; unsigned NOT_WR:1; } ; struct { unsigned RE0:1; unsigned RE1:1; unsigned RE2:1; } ;} PORTEbits ;

extern volatile far union { struct { unsigned RC0:1; unsigned RC1:1; unsigned RC2:1; unsigned RC3:1; unsigned RC4:1; unsigned RC5:1; unsigned RC6:1; unsigned RC7:1; } ; struct { unsigned AD0:1; unsigned AD1:1; unsigned AD2:1; unsigned AD3:1; unsigned AD4:1; unsigned AD5:1; unsigned AD6:1; unsigned AD7:1; } ;} PORTCbits ;extern far unsigned char DDRD;extern far struct { unsigned RD0:1; unsigned RD1:1; unsigned RD2:1; unsigned RD3:1; unsigned RD4:1; unsigned RD5:1; unsigned RD6:1; unsigned RD7:1;} DDRDbits ;extern volatile far unsigned char PORTD;


P17c44.h (cont.)extern far struct { unsigned :6; unsigned DC0:1; unsigned DC1:1;} PW1DCLbits ;extern far unsigned char PW2DCL;extern far struct { unsigned :5; unsigned TM2PW2:1; unsigned DC0:1; unsigned DC1:1;} PW2DCLbits ;extern far unsigned char PW1DCH;extern far struct { unsigned DC2:1; unsigned DC3:1; unsigned DC4:1; unsigned DC5:1; unsigned DC6:1; unsigned DC7:1; unsigned DC8:1; unsigned DC9:1;} PW1DCHbits ;extern far unsigned char PW2DCH;extern far struct { unsigned DC2:1; unsigned DC3:1; unsigned DC4:1; unsigned DC5:1; unsigned DC6:1; unsigned DC7:1; unsigned DC8:1; unsigned DC9:1;} PW2DCHbits ;extern volatile far unsigned char CA2L;extern volatile far unsigned CA2;extern volatile far unsigned char CA2H;extern far unsigned char TCON1;

extern far unsigned char PIR;extern far struct { unsigned RCIF:1; unsigned TXIF:1; unsigned CA1IF:1; unsigned CA2IF:1; unsigned TMR1IF:1; unsigned TMR2IF:1; unsigned TMR3IF:1; unsigned RBIF:1;} PIRbits ;extern far unsigned char PIE;extern far struct { unsigned RCIE:1; unsigned TXIE:1; unsigned CA1IE:1; unsigned CA2IE:1; unsigned TMR1IE:1; unsigned TMR2IE:1; unsigned TMR3IE:1; unsigned RBIE:1;} PIEbits ;extern volatile far unsigned char TMR1;extern volatile far unsigned char TMR2;extern volatile far unsigned TMR3;extern volatile far unsigned char TMR3L;extern volatile far unsigned char TMR3H;extern far unsigned char PR1;extern far unsigned char PR2;extern volatile far unsigned CA1;extern volatile far unsigned char PR3L;extern volatile far unsigned char CA1L;extern far unsigned PR3;extern volatile far unsigned char PR3H;extern volatile far unsigned char CA1H;extern far unsigned char PW1DCL;


P17c44.h (cont.)

/* Declare the function pointers the interrupt handlers will use. * We can put these in the general purpose header since this * doesn't allocate any space. If the user doesn't link in the * interrupt module for this processor, these don't do anything. */extern void (*fpINT)(void);extern void (*fpTMR0) (void);extern void (*fpT0CKI) (void);extern void (*fpPIV)(void);

/* Macros for installing interrupt functions. */#define Install_INT(isr) { fpINT = isr; }#define Install_TMR0(isr) { fpTMR0 = isr; }#define Install_T0CKI(isr){ fpT0CKI = isr; }#define Install_PIV(isr) { fpPIV = isr; }/* Define some useful macros for inline assembly stuff */#define Nop() {_asm nop _endasm}#define ClrWdt() {_asm clrwdt _endasm}#define Sleep() {_asm sleep _endasm}#define Rrcf(f) {_asm banksel f rrcf f _endasm}#define Rrncf(f) {_asm banksel f rrncf f _endasm}#define Rlcf(f) {_asm banksel f rlcf f _endasm}#define Rlncf(f) {_asm banksel f rlncf f _endasm}#define Swapf(f) {_asm banksel f swapf f _endasm}#define n_Rrcf(f) {_asm rrcf f _endasm}#define n_Rrncf(f) {_asm rrncf f _endasm}#define n_Rlcf(f) {_asm rlcf f _endasm}#define n_Rlncf(f) {_asm rlncf f _endasm}#define n_Swapf(f) {_asm swapf f _endasm}

#endif#pragma list

extern far struct { unsigned TMR1CS:1; unsigned TMR2CS:1; unsigned TMR3CS:1; unsigned T16:1; unsigned CA1ED0:1; unsigned CA1ED1:1; unsigned CA2ED0:1; unsigned CA2ED1:1;} TCON1bits ;extern far unsigned char TCON2;extern far union { struct { unsigned TMR1ON:1; unsigned TMR2ON:1; unsigned TMR3ON:1; unsigned CA1:1; unsigned PWM1ON:1; unsigned PWM2ON:1; unsigned CA1OVF:1; unsigned CA2OVF:1; } ; struct { unsigned :3; unsigned NOT_PR3:1; } ;} TCON2bits ; #pragma varlocate sfr 0 PORTA

... long list of varlocates removed

#pragma varlocate sfr 3 TCON2bits


Interrupt Functions


int16.h#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: int16.h ** Date: 16 April 1997 ** File Version: 2.10 *********************************************************************** Functions: ** Header file *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for V1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __INT16_H#define __INT16_H

// Global Interrupt Function Declarationsvoid Enable(void); // Enable global interruptsvoid Disable(void); // Disable global interrupts

// RA0/INT Config Bit Defines#define INT_ON 0b11111111 // RA0/INT interrupts on#define INT_OFF 0b01111111 // RA0/INT interrupts off#define INT_RISE_EDGE 0b11111111 // Interrupt on rising edge#define INT_FALL_EDGE 0b11111110 // Interrupt on falling edge

// RAO/INT Function Declarationsvoid OpenRA0INT(static unsigned char); // Configure RA0/INT interruptvoid CloseRA0INT(void); // Disable RA0/INT interrupt

#endif#pragma list


I/O Port Functions


I/O Port Functions (cont.)


Portb16.h#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: portb16.h ** Date: 16 April 1998 ** File Version: 2.10 *********************************************************************** Functions: ** Header file *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for V1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __PORTB16_H#define __PORTB16_H

// PORTB Config Bit Defines#define PORTB_CHANGE_INT_ON 0b11111111 // PORTB interrupts on#define PORTB_CHANGE_INT_OFF 0b01111111 // PORTB interrupts off#define PORTB_PULLUPS_ON 0b11111110 // PORTB pullups on#define PORTB_PULLUPS_OFF 0b11111111 // PORTB pullups off

// PORTB Function Declarationsvoid OpenPORTB(static unsigned char); // Configure PORTB interrupts,resistorsvoid ClosePORTB(void); // Disable PORTB interrupts, resistorsvoid EnablePullups(void); // Enable PORTB resistorsvoid DisablePullups(void); // Disable PORTB resistors

#endif#pragma list


Pulse Width Modulation Functions


Pulse Width Modulation Functions (cont.)


Pwm16.h#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: pwm16.h ** Date: 14 April 1998 ** File Version: 2.10 *********************************************************************** Functions: ** Header file *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for 1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __PWM16_H#define __PWM16_H

// PWM Duty Cycle unionunion PWMDC{

unsigned int lpwm;char bpwm[2];

};

// PWM Config Bit Defines#define T1_SOURCE 0b11111110 // Timer1 clock source#define T2_SOURCE 0b11111111 // Timer2 clock source

// PWM1 Function Declarationsvoid OpenPWM1(static char); // Configure clock, period and interruptvoid SetDCPWM1(static unsigned int); // Write duty cyclevoid ClosePWM1(void); // Disable PWM and interrupt

// PWM2 Function Declarationsvoid OpenPWM2(static unsigned char,char); // Configure clock, period and interruptvoid SetDCPWM2(static unsigned int); // Write duty cyclevoid ClosePWM2(void); // Disable PWM and interrupt


Pwm16.h (cont.)

#if defined(__17C752)||defined(__17C756)||defined(__17C756A)||defined(__17C766)||defined(__17C762)// PWM3 Function Declarations

void OpenPWM3(static unsigned char,char); // Configure clock, period and interruptvoid SetDCPWM3(static unsigned int); // Write duty cyclevoid ClosePWM3(void); // Disable PWM and interrupt#endif

#endif#pragma list


Timer Functions


Timer Functions (cont.)


Timers16.h#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: timers16.h ** Date: 14 April 1998 ** File Version: 2.10 *********************************************************************** Functions: ** Header file *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for V1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __TIMERS16_H#define __TIMERS16_H

// Union for reading and writing timersunion Timers{

unsigned int lt;char bt[2];

};

// Timer Config Bit Defines#define TIMER_INT_ON 0b11111111 // Interrupts on#define TIMER_INT_OFF 0b01111111 // Interrupts off

// Timer0 Config Bit Defines#define T0_EDGE_FALL 0b11011111 // External falling edge clocks timer#define T0_EDGE_RISE 0b11111111 // External rising edge clocs timer#define T0_SOURCE_EXT 0b10111111 // External clock source#define T0_SOURCE_INT 0b11111111 // Internal clock source


Timers16.h (cont.)

#define T0_PS_1_1 0b11100001 // Prescaler 1:1#define T0_PS_1_2 0b11100011 // 1:2#define T0_PS_1_4 0b11100101 // 1:4#define T0_PS_1_8 0b11100111 // 1:8#define T0_PS_1_16 0b11101001 // 1:16#define T0_PS_1_32 0b11101011 // 1:32#define T0_PS_1_64 0b11101101 // 1:64#define T0_PS_1_128 0b11101111 // 1:128#define T0_PS_1_256 0b11111111 // 1:256

// Timer0 Function Declarationsvoid OpenTimer0(static unsigned char); // Configures Timer0void CloseTimer0(void); // Disables Timer0unsigned int ReadTimer0(void); // Reads Timer0 registersvoid WriteTimer0(static unsigned int); // Writes Timer0 registers

// Timer1 Config Bit Defines#define T1_SOURCE_INT 0b11111110 // Internal clock source#define T1_SOURCE_EXT 0b11111111 // External clock source#define T1_T2_8BIT 0b11111101 // 8-bit mode#define T1_T2_16BIT 0b11111111 // 16-bit mode

// Timer1 Function Declarationsvoid OpenTimer1(static unsigned char); // Configures Timer1void CloseTimer1(void); // Disables Timer1unsigned char ReadTimer1(void); // Reads Timer1void WriteTimer1(static unsigned char); // Writes Timer1

// Timer1:Timer2 Function Declarationsunsigned int ReadTimer1_16(void); // Reads 16-bit Timer2:Timer1void WriteTimer1_16(static unsigned int); // Writes 16-bit Timer2:Timer1


Timers16.h (cont.)

// Timer2 Config Bit Defines#define T2_SOURCE_INT 0b11111110 // Internal clock source#define T2_SOURCE_EXT 0b11111111 // External clock source

// Timer2 Function Declarationsvoid OpenTimer2(static unsigned char); // Configures Timer2void CloseTimer2(void); // Disables Timer2unsigned char ReadTimer2(void); // Reads Timer2void WriteTimer2(static unsigned char); // Writes Timer2

// Timer3 Config Bit Defines#define T3_SOURCE_INT 0b11111110 // Internal clock source#define T3_SOURCE_EXT 0b11111111 // External clock source

// Timer3 Function Declarationsvoid OpenTimer3(static unsigned char); // Configures Timer3void CloseTimer3(void); // Disables Timer3unsigned int ReadTimer3(void); // Reads Timer3void WriteTimer3(static unsigned int); // Writes Timer3

#endif#pragma list


Capture Input Functions


Capture Input Functions (cont.)


Captur16.h#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: captur16.h ** Date: 16 April 1998 ** File Version: 2.10 *********************************************************************** Functions: ** Header File *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for 1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __CAPTUR16_H#define __CAPTUR16_H

// Capture Status Bytestruct capstatus{

unsigned Cap1OVF:1;unsigned Cap2OVF:1;unsigned Cap3OVF:1;unsigned Cap4OVF:1;unsigned :4;

};

// Union for captureunion CapResult{

unsigned int lc;char bc[2];

};


Captur16.h (cont.)// Capture Config Bit Defines#define CAPTURE_INT_ON 0b11111111 // Interrupt on#define CAPTURE_INT_OFF 0b11111110 // Interrupt off

// Capture1 Config Bit Defines#define C1_EVERY_FALL_EDGE 0b11001111 // Every falling edge#define C1_EVERY_RISE_EDGE 0b11011111 // Every rising edge#define C1_EVERY_4_RISE_EDGE 0b11101111 // Every 4th rising edge#define C1_EVERY_16_RISE_EDGE 0b11111111 // Every 16th rising edge#define CAPTURE1_PERIOD 0b11111101 // Make capture1 a period#define CAPTURE1_CAPTURE 0b11111111 // Make capture1 a capture

// Capture1 Function Declarationvoid OpenCapture1(static unsigned char); // Setup capture1unsigned int ReadCapture1(void); // Read the capture1 resultsvoid CloseCapture1(void); // Disable capture1

// Capture2 Config Bit Defines#define C2_EVERY_FALL_EDGE 0b00111111 // Every falling edge#define C2_EVERY_RISE_EDGE 0b01111111 // Every rising edge#define C2_EVERY_4_RISE_EDGE 0b10111111 // Every 4th rising edge#define C2_EVERY_16_RISE_EDGE 0b11111111 // Every 16th rising edge

// Capture2 Function Declarationvoid OpenCapture2(static unsigned char); // Setup capture2unsigned int ReadCapture2(void); // Read the capture2 resultsvoid CloseCapture2(void); // Disable capture2



Captur16.h (cont.)

#if defined(__17C752)||defined(__17C756)||defined(__17C756A)||defined(__17C766)||defined(__17C762)// Capture3 Function Declarationvoid OpenCapture3(static unsigned char); // Setup capture3unsigned int ReadCapture3(void); // Read the capture3 resultsvoid CloseCapture3(void); // Disable capture3


// Capture4 Function Declarationvoid OpenCapture4(static unsigned char); // Setup capture4unsigned int ReadCapture4(void); // Read the capture4 resultsvoid CloseCapture4(void); // Disable capture4#endif

#endif#pragma list


Reset Functions


Reset Functions (cont.)


Reset.h (cont.)#pragma nolist/********************************************************************* PICmicro C Libraries V2.10 ** Written and Tested using MPLABC V2.10 *********************************************************************** Filename: reset16.h ** Date: 14 April 1998 ** File Version: 2.10 *********************************************************************** Functions: ** Header file *********************************************************************** Revision History: ** V1.00 - Beta release of Peripheral Libraries for V1.21 ** V2.00 - Release of Peripheral Libraries for V2.00 ** V2.10 - Release of Peripheral Libraries for V2.10 *********************************************************************** Notes: ** - ROM usage varies depending on specified device *********************************************************************/#ifndef __RESET16_H#define __RESET16_H

#define WDT_ENABLED#define BOR_ENABLED

#if defined(__17C756)char isMCLR(void); // MCLR reset?void StatusReset(void); // Reset the POR and BOR bits#endif

#if defined(BOR_ENABLED)char isBOR(void); // BOR reset?#endif

#if defined(WDT_ENABLED)char isWDTTO(void); // WDT timeout during operation?char isWDTWU(void); // WDT timeout during sleep?#endif

char isPOR(void); // POR reset?char isWU(void); // Wakeup during sleep?

#endif#pragma list


Intel 8051 Microcontroller

The Intel 8051 8-bit microcontroller is one of the most frequently used

There are a number of different variations, some even from other manufacturers an example implementation (8XC51FX) includes:

12/24/33 MHz operation 8K/16K/32K On-chip program memory 256 bytes On-Chip data RAM 64K of external program and 64K of external data memory space Three 16-bit timer/counters Programmable counter array with:

High Speed Output Compare/Capture Pulse Width Modulator Watchdog Timer capability

32 programmable I/O lines 7 interrupt sources


Intel 8051 Microcontroller


Intel 8051 Microcontroller Instruction Set


Intel 8051 Microcontroller Instruction Set (cont.)


Intel 8051 Microcontroller Architecture


Intel 8051 Microcontroller Pinout


Intel 80296SA Microcontroller

A 16-bit microcontroller 50MHz operation 6Mbytes of address space 512 bytes of register RAM - 2Kbytes of Code/Data RAM 32 I/O ports 19 Interrupt sources with 14 programmable priorities 4 External interrupt pins (one NMI pin) 2 16-bit timer/counters 3 Pulse Width Modulator outputs Full-duplex serial port 4 high-speed capture/compare channels 80 Ns multiply accumulate 880 Ns 32/16 bit unsigned division


Intel 80296SA Microcontroller Architecture


Intel 80296SA Microcontroller Pinout


Atmel AT90S1200 Microcontroller

8-bit RISC microcontroller (89 instructions) 32 x 8 registers (data RAM) 1K byte on-chip program Flash memory 64 bytes on-chip EEPROM One 8-bit timer/counter with separate prescaler On-chip analog comparator Programmable watchdog timer with on-chip oscillator SPI serial interface for in-system programming 15 programmable I/O lines Low-power idle and power down modes External and Internal interrupt sources


Atmel AT90S1200 Microcontroller Architecture


Atmel AT90S1200 Microcontroller Pinout


Motorola MMC2001 Microcontroller

32-bit RISC processor core On-chip 256 Kbyte ROM On-chip 32 Kbyte SRAM with battery backup supply support Support for 32 interrupt sources External Interface Module:

transfers information between processor and external memory or peripherals

20 address and 16 data lines Bus watchdog timer

On-chip UART and separate SPI interface modules 16-bit I/O port with keyboard support 8-bit I/O port with support for edge/level sensitive external interrupts Six independent PWM channels Timer/Reset Module:

Time-of-day timer runs from external crystal Watchdog timer Periodic interrupt timer


Motorola MMC2001 Microcontroller Architecture


Motorola MMC2001 Microcontroller Pinout

egre 427 advanced digital design introduction to microcontrollers application-specific integrated...

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