Sony KV-32XBR400, Training Manual

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47
Communications
There are three communications networks used in this DX-1A TV chas-
sis. All three consist of only clock and data lines running on a parallel
connection with multiple ICs.
Communications Networks
Network Location Purpose
0
(clock 0, data 0 lines)
IC701/pin
29, 30 Dedicated communications to
the two NVM on the A & D
boards (IC707 & IC5501.
1
(clock 1, data 1 lines)
IC701/pin
28, 31 Main IIC bus to provide
direction to most ICs on the A,
B, & D boards
2 B Bd.
IC3090 to
IC3089 &
IC3408 Multi Image Driver (MID)
uCom CI3090 communications
link with driver IC3408 and
NVM (memory) IC3089.
Communications Network 0 & 1
Main uCom IC701 generates the clock signal for communications net-
work 0 and 1. Network 0 is used by IC701 to read and write data to NVM
IC707 (A board) and IC5501 (D board). Network 1 is used to send data to
most of the ICs in the TV set.
At power ON, the user data in IC707 and deflection data in IC5501 is
retrieved by IC701 using network 0 and passed to the appropriate ICs
using network 1. Once the ICs on network 1 receive this data to set their
operating parameters, the TV can function.
The Y/C CRT Drive IC201 on the A board and MID uCom IC3090 on the
B board can provide return (reply) data to IC701. This data either up-
dates the on-screen display menu (OSD is in IC701) or initiates a safety
shutdown of the TV.
The data at both network 0 and network 1 is always present as long as the
TV is ON. The first scope shot shows the network 0 data being read from
NVM IC707 and IC5501. The clock and data lines from IC701 are con-
nected to both memories in parallel. The first group of communications
goes to IC707. IC5501 is hard wired differently at pins 2 and 3 to accept
the second communications group from IC701.
c h 3
c h 2
c h 1
C H 1 !5 .0 0 V =
C H 2 !5 .0 0 V = S T O P
C H 3 !5 .0 0 V = C H P M T B 5 .0 0 m s - 2 .5 8 d v c h 1 -
1
2
3
T
Memory Communications - TV Channel 7 displayed
Scope Channel Name Location Voltage
1 WP (read/write) CN702/pin 8 5Vdc
2 Clock CN703/pin 1 5Vp-p
3 Data CN703/pin 2 5Vp-p
Time base = 5msec/div.
In this second scope shot, when the TILT rotation number is changed
from the setup menu, the WP pulse (ch 1) goes LOW when the network 0
is communicating with IC707. This allows IC701 to write the new rotation
number into NVM IC707.