Philips PM2519 - Page 31

Fiow-chart of the sequence:
RESET
AZC 120
LOAD TIMER WITH
T1 (WAIT-TIME },
CHANGE AZC
AND AZC1,
ENABLE TIMER
DISABLE TIMER,
LOAD TIMER WITH
T2 (COUNT-TIME },
ENABLE TIMER,
COUNT DATA IN
DATA COUNTER
TIMER
OVERFLOW
AZC 1=0 NO
GENERATE
INTERRUPT
("READY")
CHANGE AZC
HALT-
ST4609
840720
Fig. 2.12. Flowchart AZC period
ADC INTERFACE
READY }& —_________
1706
R1705
01703
00.0071
R1719
tot
ST4410
840713
Fig. 2.13. ADC interface
Besides these functions, the ADC interface has eight output latches to control to analog section (input
sensitivities, output current OQ 0063 etc.). One of the latches is used to give an a.c. signal which is used for
the bleeper.