Asic (ic1) – Panasonic KX-FT21RS User Manual
Page 101
6.3.2.
ASIC (IC1)
This custom IC is used for general FAX operations.
1. CPU
This model uses a Z80 equivalent CPU operating at 6MHz.
Many of the peripheral functions are handled by custom designed LSIS. As a result, the CPU only needs to process the result.
2. RTC
Real time clock.
3. DECODER
Decodes the address.
4. MODEM
Execute modulation and demodulation for the FAX.
5. ROM/RAM I/F
Controls the SELECT signal of ROM or RAM and bank switching.
6. CIS I/F
Controls document reading.
7. IMAGE DATA RAM
This is inside the ASIC and has 8KB which is used for image processing.
8. THERMAL HEAD I/F
Transmits the recorded data to the thermal head.
9. MOTOR I/F
Controls the motor which feeds the document and feeds the reading document.
10. OPERATION PANEL I/F
Serial interface with Operation Panel.
11. I/O PORT
I/O Port Interface (for analog board port control).
12. ANALOG UNIT
Electronic volume for the handset and monitor.
Sends beep tones, etc.
Explanation of the Pin Distribution (IC1)
Pin
Pin Name
Buffer Power supply
5V Tolerant
Signal Name
I/O
Description
1
X32OUT
VDDRTC
-
X32OUT
32.768kHz oscillator for RTC (built-in feed back
resistor)
2
X32IN
VDDRTC
NO
X32IN
32.768kHz oscillator for RTC (built-in feed back
resistor)
3
VDDRTC
+3.3V/BATT
32.768kHz backup power supply for RTC
4
XBACKEN
VDDRTC
YES
XRESET
Backup enable
5
VDDSRAM
+3.3V/BATT
RAMCS buffer/backup power supply for reset
6
XRAMCS
VDDSRAM
-
VDDSRAM
SRAM chip select ("H": 3.3V or BATT)
7
XRAMCE2/ALARM
VDDSRAM
-
OPEN
Not used
8
FTG
MULT3/5
NO
FTG
O FTG
9
F1
MULT3/5
NO
F1
O F1 (50%/75% selector)
10
MULT3/5
+5V
Power supply
11
VSS
DG
Ground
12
F2/OP50
MULT3/5
NO
E
O LCD control
13
FR/OP51
MULT3/5
NO
OPEN
O Not used
14
XRESET
3.3V
YES
XRESET
Reset input for internal digital circuit
15
VSS
DG
Ground
16
XORESET
3.3V
-
XORESET
Reset output
17
XRESETI
3.3V
YES
XRESETI
Voltage detector IC output for reset
18
XWDERR
3.3V
YES
XWDERR
Watch dog timer error
19
XRSTSWO/OP82
3.3V
YES
OPEN
O Not used
20
VIDRST/IOP20
3.3V
YES
OPEN
O Not used
21
SPHCLK/IOP21
3.3V
YES
OPEN
O Not used
22
DARKON/IOP22
3.3V
YES
OPEN
O Not used
23
ADSEL2/IOP23
3.3V
YES
OPEN
O Not used
24
BELL/OP
3.3V
YES
OPEN
O Not used
25
3.3V
+3.3V
Power supply
101
KX-FT21RS