EL21C COURSE TEST #2

WEDNESDAY 21st NOVEMBER 2001

MICROPROCESSORS I

Time: (2:00 - 3:00 )PM

( 1 ) State and define the minimum amount of signals necessary to interface a 12-bit A/D

converter to the SDK-85 kit. [4]

( 2 ) Using the SDK-85 kit, write assembly mnemonic code to read port 21H, store the value into

memory location 1000H, and write it out to port 22H. [4]

( 3 ) Specify the output at PORT1 if the following program is executed. [2]

MVI B,0D2H

MOV A,B

MOV C,A

MVI D,53H

OUT PORT1

HLT

( 4 ) What are the contents of the CSR, of the 8155, when Port A is an input port and Ports B

and C are output ports? [2]

( 5 ) Using Fig.1, determine the size of the memory IC's shown, both address size and data

size. [2]

[2]

( 6 ) Describe how SIM and RIM are used in serial transmission. [4]

( 7 ) Sketch the waveshape of the asynchronous serial transmission of the ASCII character

H (48H) using 33.3 kbaud, 8-data bits, even parity, and 1-stop bit. [3]

( 8 ) Using the A/D you explained in Question 1 to interface to the SDK-85 kit, write software to

take a reading and store it in memory location 20B0H. [9]

Bonus mark:

There is a sign on my office door which reads:

“SILENCE ”

Fill in the blank spaces.

Maximum = 30

N.B: Please attend the seminar on Monday (26^th in SLT @ 1:00pm)

for those interested in graduate work after B.Sc.