;
|
;
|
; rom03.s -- terminal echo, polled
|
; rom03.s -- terminal echo, polled
|
;
|
;
|
|
|
.set tba,0xF0300000 ; terminal base address
|
.set tba,0xF0300000 ; terminal base address
|
|
|
add $8,$0,tba ; set terminal base address
|
add $8,$0,tba ; set terminal base address
|
L1:
|
L1:
|
ldw $9,$8,0 ; load receiver status into $9
|
ldw $9,$8,0 ; load receiver status into $9
|
and $9,$9,1 ; check receiver ready
|
and $9,$9,1 ; check receiver ready
|
beq $9,$0,L1 ; loop while not ready
|
beq $9,$0,L1 ; loop while not ready
|
ldw $10,$8,4 ; load receiver data into $10
|
ldw $10,$8,4 ; load receiver data into $10
|
L2:
|
L2:
|
ldw $9,$8,8 ; load transmitter status into $9
|
ldw $9,$8,8 ; load transmitter status into $9
|
and $9,$9,1 ; check transmitter ready
|
and $9,$9,1 ; check transmitter ready
|
beq $9,$0,L2 ; loop while not ready
|
beq $9,$0,L2 ; loop while not ready
|
stw $10,$8,12 ; load char into transmitter data
|
stw $10,$8,12 ; load char into transmitter data
|
j L1 ; all over again
|
j L1 ; all over again
|
|
|
