Philips CEM2100/00 Service Manual page 209

Example :Duty measurement (resolution fc/2
PINTTC1:
SINTTC1:
VINTTC1:
TC1 pin
INTTC1 interrupt request
INTTC1SW
7
[Hz])
CLR (INTTC1SW). 0
LD (TC1CR), 00000110B
DI
SET (EIRL). 5
EI
LD (TC1CR), 00100110B
:
CPL (INTTC1SW). 0
JRS F, SINTTC1
LD A, (TC1DRBL)
LD W,(TC1DRBH)
LD (HPULSE), WA
RETI
LD A, (TC1DRBL)
LD W,(TC1DRBH)
LD (WIDTH), WA
:
RETI
:
DW PINTTC1
HPULSE
Page 87
; INTTC1 service switch initial setting
Address set to convert INTTC1SW at each INTTC1
; Sets the TC1 mode and source clock
; IMF= "0"
; Enables INTTC1
; IMF= "1"
; Starts TC1 with an external trigger at MCAP1 = 0
; INTTC1 interrupt, inverts and tests INTTC1 service switch
; Reads TC1DRB (High-level pulse width)
; Stores high-level pulse width in RAM
; Reads TC1DRB (Cycle)
; Stores cycle in RAM
; Duty calculation
; INTTC1 Interrupt vector
WIDTH
T5CL8