Sony S530D manual Parallel Data Communications, Chip Select Line, HGA IC601

Parallel Data Communications

There are six ICs that communicate with System Control IC202 on the parallel bus:

ICs on the Parallel Bus

	Name	Number	Purpose
1.	Flash ROM	IC205	Start up program instructions
2.	Hybrid Gate	IC601	Expansion port for System Control
	Array		IC202
3.	SRAM	IC204	IC202’s local memory
4.	AV Decoder	IC401	Audio (AC-3) and Video (MPEG 2)
			decoder
5.	ARP2	IC303	CD/DVD data processing & separation
6.	Servo DSP	IC701	Analog servo control

Bi-directional communications between these ICs are accomplished us- ing the following lines; however, not all ICs use the last three lines:

·Chip Select from IC202

·Address from IC202

·Data (bi-directional)

·Clock from IC202

·Interrupt from destination IC

·Read/Write from IC202

Chip Select Line

System Control IC202 systematically polls each IC on the communica- tions bus with a chip select signal. This low or high going pulse identifies the individual destination IC that System Control wants to communicate with. The chip select output sequence is listed below:

27

Chip Select Signals from IC202 (active low)

	CS Source	Destination	Pulse
			Width/Polarity
1.	CS 1 - IC202/pin 10	SRAM IC204 /	0.56us /–
		HGA IC601	0.9usec/-
2.	CE – IC202/pin 11	Flash ROM IC205	0.56us /–
3.	CS 2 – IC202/pin 9	AV Decoder IC401	0.7 & .26
			usec/-
4.	CS 4 – IC202/pin 7	HGA IC601	0.3usec/-
5.	CS 3 – IC202/pin 8	AV Decoder IC401	1.2usec/-
6.	XCS – IC601/pin 111	ARP2 IC303	0.3usec/-
7.	HCS - IC601/pin 118	Servo IC701	0.3usec/-

Chip Select Waveforms

The following waveforms show the chip select signals going to the S RAM IC204 (ch 1) and AV Decoder IC401 (ch 2 and 3). They can be compared to the D1 data (ch 4) to show that the chip select (ch 1-3) signals occupy more than one bit clock interval. Note that on each of the CS 1 (ch 1) and CS 2 (ch 2) lines, two different pulse widths are used. These waveforms were taken with the unit on without a disc being played.

	P M 3 3 9 4 , F L U K E & P H I L I P S
ch1
ch2	1

ch3

T

2

ch4

3

CH1!5 . 00 V=

CH2!5 . 00 V=

C H 3!5 . 00 V= 4

CH4!2 . 00 V= ALT MTB5 . 00us - 1 . 34dv ch2 -

Chip Select signals from IC202 (active low)

	Name	Location	Voltage/div
Channel 1	CS = CS1	IC202/pin 10	5Vp-p
Channel 2	CS = CS2	IC202/pin 9	5Vp-p
Channel 3	CS = CS3	IC202/pin 8	5Vp-p
Channel 4	Data = D1	IC202/pin 26	2Vp-p
Time base		5usec/div.