ExEsame10.asm

;Exercise on slide 10: June 2nd, 2000 exam

org 400h
device equ 0h         ;Interrupts CPU every 10 ms, checks if devtemp > maxtemp
                      ;If so, disables device interrupts and sets DMAC to send alarm message
                      ;When transfer is over, enables device and interrupts CPU
devtemp equ 1h        ;Measures temperature
dmac equ 2h           ;DMAC
video equ 3h          ;Video output device, acquires alarm message
buffer equ 0BBBBh     ;Initial memory buffer, alarm starts here
maxtemp equ 400       ;Maximum possible temperature in decimals of °C
code
jsr init
main: jmp main        ;Loops until interrupt
halt
init: start device    ;Initializing routine
start devtemp
setim device
seti
ret
driver 0, 700h
push R0
inb devtemp, R0
cmpb maxtemp, R0      ;Checks if devtemp > maxtemp WARNING: SYNTAX TO BE CHECKED
jn alert              ;If so, sends alarm message to video
pop R0
rti
alert: clrim device   ;Disables device interrupts
outl #512, WC         ;Stars word counter at 512
outl buffer, CAR      ;Starts CAR at current memory buffer
start dmac
setim dmac            ;Enables DMAC interrupt
pop R0
rti
driver 2, 900h
clrim dmac            ;Disables DMAC interrupt
start device
setim device
rti
end