59
IC202 to IC601 Communications
Signal Active Signal Present when
Chip Select (CS1 or CS4) Low IC202 & IC205 gets Vcc
Clock IC202/pin 5 Low IC202 gets B+
Write IC202/pin 22 Low IC202 & IC205 gets Vcc
Six Address lines HA 0-5 IC202 gets B+
16 Data lines HD 0-15 IC202 gets B+

When IC601 wants to send reply data to IC202, an interrupt signal is sent

to IC202. When IC202 is ready, it will send chip select, clock, read pulses

and address to support the data received from IC601.

IC601 to IC202 Communications
Signal Active Signal Present when
Interrupt (INT1 or INT3) Low An operation is completed
(e.g. sled moved)
Chip Select (CS1 or CS4) Low IC202 and IC205 gets Vcc
Clock IC202/pin 5 Low IC202 gets B+
Read IC202/pin 24 Low IC202 and IC205 gets Vcc
Six Address lines HA 0-5 IC202 gets B+
16 Data lines HD 0-15 IC202 gets B+
HGA IC601 to Servo IC701

Bi-directional communications between these two ICs is similar to that

described for IC202 and IC601. The differences are in the IC pin num-

bers and that IC601-IC701 communications are only taking place when a

servo command is changed.

IC601 to IC701 Communications
Signal Active Signal Present when
Chip Select (SDCPS
IC601/pin 118) Low Power on/off, Tray in/out,
disc playback
Clock Input IC701/pin 108 Low 3.3V is present
Write (SDPWR IC601/pin
116) Low Power on/off, Tray in/out,
disc playback
Two Address lines HA 0-1 IC202 gets Vcc
8 Data lines HD 0-7 IC202 gets Vcc
IC701 to IC601 Communications
Signal Active Signal Present when
Interrupt
(
HINT from
IC701/pin 128) Low An operation is completed
(e.g. sled moved)
Chip Select
(
SDCPS
from IC601/pin 118) Low Power on/off
,
Tra
y
in/out
,
disc playback
Clock Input IC701/pin
108 Low 3.3V is present
Read from IC601/pin
117 Low Power on/off
,
Tra
y
in/out
,
disc playback
Two Address lines HA
0-1 IC202 gets Vcc
8 Data lines HD 0-7 IC202 gets Vcc