Panasonic KX-FT21BX

KX-FT21LA
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3. CONTROL SECTION
1. 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 Pow er 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 pow er 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
Pow er 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
Pow er supply
26
IRDATXD/IOP81 3.3V
YES OPEN O
Not used
27
IRDARXD/IOP80 3.3V
YES OPEN O
Not used
28
TXD/IOP30 3.3V
YES OPEN O
Not used
29
RXD/IOP31 3.3V
YES OPEN O
Not used
30
XRTS/IOP32 3.3V
YES OPEN O
Not used
31
XCTS/IOP33 3.3V
YES OPEN O
Not used
32
XDSR/IOP34 3.3V
YES OPEN O
Not used
33
DCD/IOP35 3.3V
YES OPEN O
Not used
34
XDTR/IOP36 3.3V
YES OPEN O
Not used
35
RI/CLK/IOP37 3.3V
YES OPEN O
Not used
36
IOP90 3.3V
YES OPEN O
Not used
37
IOP91 3.3V
YES OPEN O
Not used