Sony S530D manual Servo DSP IC701 Issues Analog Commands to Driver IC802, Sled Still Sled Outward

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

IC601 and IC701 Communications

	Name	From IC	When Present
1.	Chip	System Control IC202	Power on/off, playback, tray
	Select		open close, and start/stop..
2.	Read	System Control IC202	Always when powered on
3.	Write	System Control IC202	Completion of command
			(PB, pause, pwr on/off)
4.	Interrupt	Servo IC701	Completion of command
			(PB, pause, pwr on/off)
Address		Bi-directional	Always when powered on
Data		Bi-directional	Always when powered on

Bi-directional communications between IC601 and IC701 are similar to that described for IC202 and IC601. The differences are in the IC pin numbers and that IC601-IC701 communications are only taking place when a servo command is changed.

Communications Waveforms

The following waveforms were taken during a sled forward command ini- tiated from the service mode. They show IC701/pin 3 being chip selected when low (ch 1). This means 16 bits of data (HD0-15) can be transferred at each clock interval when this line is low. The chip select pulse is as wide as three clock intervals. Consequently three groups of data (HD0- 15 =16 bits) can be written or read by IC202.

The write line (ch 3) goes low during the chip select interval (ch 1) to identify the direction of the (sled forward) bus data into Servo IC701. The read line is high during this time, meaning it is inactive. The interrupt signal will go low later on after the sled fast forward movement has been completed (ch 4).

ch1

ch2

1

ch3

ch4

2

3

CH1!2 . 00 V=

CH2!2 . 00 V=

43

IC601 to IC701 Communications Waveforms

	Name	Location	Voltage/div
Channel 1	Chip Select (HCS)	IC701/pin 3	2Vp-p
Channel 2	Read (HRD)	IC701/pin 1	2Vp-p
Channel 3	Write (HWR)	IC701/pin 2	2Vp-p
Channel 4	Interrupt (HINT)	IC701/pin 128	2Vp-p
Time base		0.25usec/div.

Servo DSP IC701 Issues Analog Commands to Driver IC802

Digital commands from IC202 (via IC601) tell Servo IC701 to perform sled operations. First IC701 sends an interrupt signal to IC202 (via IC601), followed by data about the in limit sensor. This data tells IC202 if the laser is at home position (IC701/pin 23 = 0.7V = home).

If the laser is not at home position, IC202 data to the Servo IC701 in- structs it to rotate the sled motor until home position is reached.

The sled output of Servo IC701 consists of three 50% duty cycle in phase square waves at about 80kHz. The square wave from IC701/pin 7 is used as reference and does not change. If the square wave from pin 8 or 9 decreases in width, the sled motor rotates. This can be seen in the following waveforms.

Sled Motor Stop Waveforms

The following waveforms were taken of the square waves from IC701 when the sled motor is not turning and when it is moving away from the spindle shaft (outward).

	P M 3 3 9 4 , F L U K E & P H I L I P S			P M 3 3 9 4 , F L U K E & P H I L I P S
	ch1: freq= 79 . 4kHz			ch1: freq= 79 . 4kHz
ch1
			ch1
ch2	T		ch2	T
ch3	1			1
			ch3
	2			2
	CH1!2 . 00 V=			CH1!2 . 00 V=
	CH2!2 . 00 V=			3CH2!2 . 00 V=
	3
	CH3!2 . 00 V= ALT MTB5 . 00us	ch1+		CH3!2 . 00 V= ALT MTB5 . 00us	ch1+
	Sled Still			Sled Outward

CH3!2 . 00 V=

CH4!2 . 00 V= ALT MTB 250ns - 1 . 06dv ch1 -