ECE 353Introduction to Microprocessor Systems

Michael G. Morrow, P.E.

Week 7

ExerciseWrite a procedure (mul32 ) that does a 32-bit multiply and returns its 32-bit result in DX:AX. Passed the two double-word parameters

using a standard stack frame. Allocate any temporary variables

required on the stack frame.

Write a code fragment that calls mul32 using two double-word operands stored in memory and stores the answer in a third double-word memory location.

Procedures Exam 1 will be held on Thursday,

October 18, 2001 from 7:15 to 8:45 PM in 132 Noland

Can use one 8½ x 11 sheet (both sides) of original, handwritten notes

Instruction set and datasheets will be provided as required.

Midterm Exam #1

Assessment Quiz1. Register used as a loop counter.2. What type of memory operations

are run for AND mem, 2?3. Registers that can be used as

sources for the OUT instruction.4. Default segment for most

memory operands.5. Assembler operator used to

inform the assembler of the type of memory access.

Assessment Quiz1. Write a code fragment that uses

rotates/shifts to fill BX with the bit-reversed value of AX.

Assessment QuizIf CS=1000h, DS=2000h, ES=3000h, SS=4000h, BX=5000h, BP=6000h, DI=7000h, SI=8000h, offset of X = 400h; find source’s logical and physical address:1.mov AX, [BP]2.mov AX, X[DI]3.mov AX, [BX]+34.mov AX, X5.mov AX, CS:X

Assessment Quiz80C188EB Hardware1. Indicates next instruction to be

fetched.2. Calculates physical addresses.3. Purpose of /S2:04. Used as the frame pointer.5. The extended accumulator.6. Source operand for IN instruction.7. Memory destination for string

operations.

Assessment QuizCode Generation1. Joins multiple object files. 2. Converts mnemonics to opcodes.3. Assigns physical addresses to

memory segments.4. Debugging technique using small

kernel on the target to communicate with host machine having main debugging software.

5. Assembler that generates code for another CPU.

Assessment QuizAddressing modes:1. Uses a register to hold operand’s

offset.2. Operand’s offset embedded in

opcode.3. Operand embedded in opcode.4. Destination mode of MOV [BP+2],

AL.5. Purpose of the ASSUME directive.

Assessment Quiz1. Effect of LOOPZ instruction.2. Restrictions on conditional jumps.3. Applicability and effect of REP

prefix.4. Effect of PUSH instruction.5. Difference between SAL and SHL.6. Ways to access a look-up table.7. How to declare constant data in

embedded system.

Assessment Quiz1. Toggle bit D5 of AL.2. Clear bit D1 of CH.3. Set D14 of AX.4. Clear word output port 0030h.5. Clear AX if D3 of byte input port

0378h is cleared.6. Use LOOP to set every element of

the word array XYZ to 0FFFFh.

Assessment Quiz1. How may iterations?

MOV CX, -1

SAL CX, 3

XORCX, 1

NOTCX

XYZ: NOP

LOOP XYZ

Assessment Quiz1. Use a look-up table to convert the

values 0-9 to their ASCII equivalents? Assume that the value to convert has been placed in DL.

1. Show the signals and timing required to transfer data from the input port to the output port.

Assessment Quiz

Wrapping UpExam 1 will be held on Thursday, October 18, 2001 from 7:15 to 8:45 PM in 132 Noland