Philips LX700/21S/22S/25S, Service Manual

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KEY / POWER SW BOARD
TABLE OF CONTENTS
IC Interbnal Block Diagram ............................................. 5-1
Circuit Diagram ................................................................ 5-2
PCB Layout Top & Bottom View ...................................... 5-3
Electrical Parts List .......................................................... 5-4
5-1 5-1
WDT TIME
OUT
8
STACK 1
STACK 2
EPROM/ROM
512 X 12 TO
2048 X 12
INSTRUCTION
REGISTER
INSTRUCTION
DECODER
WATCHDOG
TIMER
CONFIGURATION WORD
OSCILLATOR/
TIMING &
CONTROL
GENERAL
PURPOSE
REGISTER
FILE
(SRAM)
24, 25, 72 or
73 Bytes
WDT/TMR0
PRESCALER
OPTION REG.
“OPTION”
“SLEEP”
“CODE
PROTECT”
“OSC
SELECT”
DIRECT ADDRESS
TMR0
FROM W
FROM W
“TRIS 5”
“TRIS 6”
“TRIS 7”
FSR
TRISA PORTA
TRISB
PORTC
TRISC
PORTB
FROM W
T0CKI
PIN
9-11
9-11
12
12
8
W
4
4
4
DATA BUS
8
8
8
8
8
8
8
ALU
STATUS
FROM W
CLKOUT
8
9
6
5
5-7
OSC1 OSC2 MCLR
LI
T
E
R
A
LS
PC
“DISABLE”
2
RA<3:0> RB<7:0>
RC<7:0>
(28-Pin
Devices Only)
DIRECT RAM
ADDRESS
Serial
Data
interface
LED
Driver
OSC
Timming
Generator
Segment
Driver/
Grid
Driver/
Key Scan
Output
Dimming
Circuit
Grid
Driver
Control
Genaral
Input
Register
Key Matrix
Memory
Genaral
Input
Register
SG1/KS1
SG2/KS2
SG3/KS3
SG4/KS4
SG5/KS5
SG6/KS6
SG7/KS7
SG8/KS8
SG9/KS9
SG10/KS10
SG11/KS11
SG12/KS12
SG13/GR16
SG14/GR15
SG15/GR14
SG16/GR13
SG17/GR12
SG18/GR11
SG19/GR10
SG20/GR9
GR1
GR2
GR3
GR4
GR5
GR6
GR7
GR8
VEE GND VDD K1
LED 5
LED 4
LED 1
SW 1
D
IN
D
OUT
CLK
STB
V
DD
OSC
R
SW 2
SW 3
SW 4
LED 2
LED 3
K2 K3 K4
CF745 INTERNAL BLOCK DIAGRAM
PT6311 INTERNAL BLOCK DIAGRAM