ECE 353Introduction to Microprocessor Systems

Michael G. Morrow, P.E.

Module #7 Assessment Quiz

ReviewWhy do PC UARTs include data FIFOs?Write 2 subroutines (in/out) with a data area to implement a circular queue of size N=2n. Why is it better to have N=2n? If this queue is being used by a serial transmitter ISR and the main program, what hazards could occur?What are the differences between synchronous and asynchronous comm?How does an asynchronous receiver know when to sample each bit? Synchronous?

ReviewA UART typically uses a clock 8x-16x the baud rate. Why?What is the purpose of the parity bit? How is it calculated?How does software flow control work?Compare and contrast hardware and software flow control.

ReviewWhat sorts of things does the RS-232 standardize?On an RS-232 link, what information needs to be known in advance at both ends?If an ADC is operating with FS=48KHz, what range of frequencies can it convert correctly?What could you do if there were higher frequencies present in the signal?How does a successive-approximation ADC work?

Review

What is IREF? Currents through all 2R?

How do the switches affect the 2R currents?Write a general equation for VOUT.

What is the digital input value?What is the value of VOUT? Range of VOUT?

What is the digital coding scheme?What would happen if we made R=Rf=10K Ω?

R

2R

2R

2R

2R

R

+8V

V OUT

R f

-

+

ITOT

IREF

ISUM

Assume R=Rf=1kΩ and the switches are as shown.

ReviewIs it DAC or ADC?What type of quantization?What is offset error?What is gain error?What is DNL spec?What is INL spec?Is it monotonic?

6/8

5/8

4/8

3/8

2/8

1/8

0

0

7/8

VO

UT

(* V

FS

)

7654321

Digital Input

Ideal transfercharacteristic

ReviewAssume a 10-bit ADC with VREF = 2.048V using an unsigned binary coding scheme.What is its resolution?What is the smallest input change that you are guaranteed to detect? (Ideal)What is the maximum binary output, and what voltage does it correspond to?If reading a temperature sensor with a 10mV/°C output (0°C-200°C), how many bits needed to be accurate to +/-0.2°C?

Assessment QuizThat’s all, folks!