Sharp XE-A212, Service Manual

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XE-A212V HARDWARE DESCRIPTION
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<Power supply/CONTROL pins>
5. KEY-DISPLAY
5-1. LCD CONTROL
Basically the same as the XE-A401 and ER-A275P.
<LCD-related registers>
< LCD Control Signal / Key Strobe Signal >
Bit7 : Not used
Bit6 : E
Enable Signal Enable
Bit5 : R/W
H : Data read L : Data Write
Bit4 : RS
H : Data input L : Instruction Input
< Data Latch Signal >
L : LCD write data latch
5-2. KEY/DISPLAY SCAN
On the machine, the key and display scan signal is common.
KEY/display SCAN and key read should be performed at the following
timing.
1
KEY/display SCAN cycle: 10ms
2
Blanking time: 50us
3
KEY DATA READ timing: More than 10 ms from the fall of the SCAN
signal
<Key/Display-related registers>
< LED Segment Signal >
… … … …
Wite
< LCD Control Signal/Key Strobe Signal >
… … … …
Write
Bit3 ~ 0 : KS3 ~ 0
Strobe signals for keys and POP UP Display are generated at KS3 - 0.
< Key Return Signal >
… … … …
Read
Normal Keyboard : 04003h
Flat Keyboard : 04003h
PORT
PIN
No.
I/O Pin name Function PORT
PIN
No.
I/O Pin name Function
BYTE 8 I BYTE Connected to VDD Vcc 62 Vcc Connected to VDD
CNVss 9 I CNVss Connected to VDD Vss 64 Vss connected to GND
/RESET 12 I /RESET AVss 96 AVss Connected to GND
Xout 13 O Xout OPEN Vref 98 Vref Connected to VDD
Vss 14 Vss Connected to GND AVcc 99 AVcc Connected to VDD
Xin 15 I Xin connected to Spectram diffusion IC
Vcc 16 Vcc Connected to VDD
Function Address R/W
LCD Write Data 04001h W
LCD Read Data 04002h R
LCD Control Signal / Key Strobe Signal 04003h W
Data Latch Signal CPU port P94 W
Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
04003h – E R/W RS KS3 KS2 KS1 KS0
Function Address R/W
LED Segment Signal 04000h W
LCD Control Signal / Key Strobe Signal 04003h W
Key Return Signal 04003h R
Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
04000h dp g f e d c b a
Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
04003h - E R/W RS KS3 KS2 KS1 KS0
Address Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
04001h - - - - KR11 KR10 KR9 KR8
04003h KR7 KR6 KR5 KR4 KR3 KR2 KR1 KR0