Toshiba 21E88, Service Manual

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SERVICE MANUAL
5). Basic Structure
5.1). Internal Connections
TMPA8801/8807 has two pieces of IC chip in one package, using Multi-Chip-Package (MCP)
technology. One is
a micro controller (MCU) and the other one is a signal processor (SP) for a color TV. There are some
internal connections between these two ICs for handling below signals.
Table 7 Signal Name Direction Description
Signal Name Direction Description
1 SCL M to S Internal IIC bus SCL
2 SDA Bi-direction Internal IIC bus SDA
3 OSD R M to S OSD signal connection
4 OSD G M to S OSD signal connection
5 OSD B M to S OSD signal connection
6 OSD Y/BL M to S OSD display control
7 OSD I, CS OUT M to S OSD half-tone control/Test pattern signal
8 C-Video S to M Composite video signal from internal video switch, for CCD
9 C-Sync S to M Composite sync. signal from sync. Separator, for CCD
10 HD S to M Horizontal timing pulse regenerated from FBP, for OSD
11 VD S to M Vertical timing pulse from sync. Separator, for OSD
12 CLK M to S 8 MHz clock
13 AV
DD
M to S Reference voltage for C-Video interface
14 ADC S to M A/D converter monitoring RF-AGC, R-Y and B-Y
Functions of SP from MCU are controllable through the IIC bus of the internal connections.
5.2). Power Supply
TMPA8801/8807 has some power supplys and GND pins. Power supplies related MCU must be
applied at the
first. Power supplies for H.VCC and TV D.VCC are the second with at least 100 ms delay after MCU
power
ON. The other power supplies are the last, which are recommended to be supplied from a regulator
circuit
using FBP.
5.3). Crystal Resonator
TMPA8801/8807 requires only one crystal resonator, in stead that a conventional two-chip solution
requires
two resonators at least, one for MCU and the other one for SP. An oscillation clock with the crystal
resonator of TMPA8801 /8807is supplied for MCU operation, PIF VCO automatic alignment, alignment
free AFT,
chroma demodulation and horizontal oscillation. The oscillation frequency is very important so that
those
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