TIMERS and TIMER/COUNTERS KS57C2308/P2308/C2316/P2316
11-6
++ PROGRAMMING TIP — Using the Basic Timer
1. To read the basic timer count register (BCNT):
BITS EMB
SMB 15
BCNTR LD EA,BCNT
LD YZ,EA
LD EA,BCNT
CPSE EA,YZ
JR BCNTR
2. When stop mode is released by an interrupt, set the oscillation stabilization interval to 31.3 ms at 4.19 MHz:
BITS EMB
SMB 15
LD A,#0BH
LD BMOD,A ;Wait time is 31.3 ms
NOP
STOP ;Get into stop for power-down mode
NOP
NOP
NOP
NORMAL
OPERATING MODE STOP MODE IDLE MODE
(31.3 ms)
CPU
OPERATION
STOP
INSTRUCTION STOP MODE IS
RELEASED BY
INTERRUPT
NORMAL
OPERATING MODE
3. To set the basic timer interrupt interval time to 1.95 ms (at 4.19 MHz):
BITS EMB
SMB 15
LD A,#0FH
LD BMOD,A
EI
BITS IEB ;Basic timer interrupt enable flag is set to "1"
4. Clear BCNT and the IRQB flag and restart the basic timer:
BITS EMB
SMB 15
BITS BMOD.3