JVC TH-A30 Service Manual page 26

TH-A30
74HCT245 (U15) : Transceiver
1.Pin layout
ENABLE
Vcc G B1 B2
20 19 18
1 2 3
DIR A1 A2
M5705 (DU3) : DVD-ROM controller
1.Block diagram
M5703/M5707
RF
Amp
M
Motor
Driver
1-26
B3 B4 B5 B6
17 16 15 14 13
4 5 6 7 8
A3 A4 A5 A6 A7
Data
Separator
DVD-DSP
Digital
CD-DSP
Servo
2.Truth table
B7 B8
12 11
H = HIGH Level
L = LOW Level
X = Irrelevant
9 10
A8 GND
4M DRAM
ATAPI
MPEG
RAM
Arbiter
C3 ECC
Target MCU
Search
ROM
Control
Operation
Inputs
G DIR 245
L L
B data to A bus
L H A data to B bus
H X
isolation
&
PC
I/F
MPEG
DEC.
EDC