Specifications

RMU800A SERVICE MANUAL
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4. Flash ROM: AT29C020-90T1(TX-RX Unit IC103)
4-1 Pin Function
Pin No. Name I/O Function
1～6, 9～20, 31 A18～A0
I Flash ROM address bus.
7 WR I Flash ROM write enable.
8 VCC +5V.
21～23, 25～29 D0～D7
I/O Flash ROM data bus.
24 VSS GND.
30 CE I Flash ROM chip enable.
32 OE I Flash ROM output enable.
5. EEPROM: AT2408N12.5S(TX-RX Unit IC105)
5-1 Pin Function
Pin No. Name I/O Function
1～3 A0～A2
I Address inputs.
4 GND GND.
5 SDA I/O Serial Data.
6 SCL Serial clock input.
7 TEST Test.
8 VCC +5V.
28 HMBL MIC backlight control signal output.
29 HOOK/RXD0 Hook signal input/ Serial data input.
30 TXD0 O PC commands (TXD)/connects to PTT.
31 RLED O Red LED output.
32 GLED O Green LED output.
33 PTT O PTT/connect to TXD0.
34 DNKEY I Up key.
35 UPKEY I Down key.
36 KEYBL I Key backlight.
37 IN1 Not used.
38 IN2 Not used.
39 PF6 I PF6 Key Input.
40 PF5 I PF5 Key Input.
41 PF4 I PF4 Key Input.
42 PF3 I PF3 Key Input.
43 PF2 I PF2 Key Input.
44 PF1 I PF1 Key Input.