EE3376 โ Embedded Systems - Spring 2007 - Exam 2 โ MacDonald โ Page 1
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Show work with intermediate steps. Showing only the answer will get no credit.
Problem 1
The following questions are related to Port A as GPIO.
a) If address $0002 contains $00 and all of the Port A pins have a 100k ohm resistor
to Vdd (5V) and 4k ohm resistor to ground, what value would you find in address
$0000?
b) Assuming the same conditions in part A, what would be the value of address
$0000 after the instruction โmovb #$ff, $0000โ was executed?
c) If address $0002 is $ff and every pin has a 100k ohm resistor to Vdd (5V), what
would be the value of address $0000 after the instruction โmovb #$00, $0000โ
was executed?
d) If address $0002 is $55 and every pin has a 100k ohm resistor to Vdd (5V), what
would be the value of address $0000 after the instruction โmovb #$00, $0000โ
was executed?
