Specifications

S1C62740 TECHNICAL SOFTWARE EPSON II-41
CHAPTER 6: PERIPHERAL CIRCUITS (Stopwatch Timer)
SWINIT:
LD X,ZSWCTL ;SET STOPWATCH CONTROL
;REGISTER ADDRESS
OR MX,0001B ;WHEN RESET STOPWATCH
;THEN (SWL,SWH) WILL BECOME (0,0)
;
DI
LD X,ZISW ;RESET INTERRUPT FLAG
LD A,MX
;
LD X,ZEISW
LD MX,0001B ;ENABLE STOPWATCH 10 Hz INTERRUPT
;
LD X,ZSWCTL
OR MX,0010B ;START THE STOPWATCH TIMER
;
EI
RET
;
;* STOPWATCH TIMER INTERRUPT
;
SWINT:
LD X,ZISW ;LOAD STOPWATCH INTERRUPT FLAG
;TO B REGISTER
LD B,MX
;
FAN B,0001B ;CHECK STOPWATCH 10 Hz
;INTERRUPT FLAG
JP Z,SWINT1 ;NO, THEN JUMP
;
LD X,ZSWL ;SET TO STOPWATCH TIMER DATA ADDRESS
LDPX A,MX ;READ STOPWATCH LOW INTO A REGISTER
LD B,MX ;READ STOPWATCH HIGH INTO B REGISTER
;:
; DO THE PROCEDURE FOR 10 Hz INTERRUPT SERVICE
;:
SWINT1:
EI
RET
;
;* STOPWATCH TIMER STOP ROUTINE
;
SWSTOP:
LD X,ZSWCTL ;STOP STOPWATCH
AND MX,1101B
RET
;