Huawei ETS2000 Series Maintenance Manual page 13

figure1-18System keypad interfaces
Serial
Signal name
No.
1 KEY_BACKLIGHT
2 STATUS_A
3 VREG_PHONE
4 VSS
5 NA
6 KPAD_ROW3
7 KPAD_ROW2
8 KPAD_ROW1
9 KPAD_ROW0
10 VSS
11 VSS
12 KPAD_COL5
13 KPAD_COL4
14 KPAD_COL3
15 KPAD_COL2
16 KPAD_COL1
17 KPAD_COL0
18 VSS
19 SPEAKER_P
20 SPEAKER_N
4. R_UIM card interface circuit
The primary function of the R_UIM card interface module is to provide the
R_UIM card connector and conduct ESD protection towards signals. The
connecting mode is shown in Table 1-3.
Direction Signal function description
Keypad back-facet drive.
O Current source output.
0--150mA.
Communication indicator
I
connecting the LED (-) end
Power supply connecting the
O
LED (+) end
IO Keypad grounding
I Keypad row scanning signal 3
I Keypad row scanning signal 2
I Keypad row scanning signal 1
I Keypad row scanning signal 0
IO Keypad grounding
IO Keypad grounding
Keypad column scanning
O
signal 5
Keypad column scanning
O
signal 4
Keypad column scanning
O
signal 3
Keypad column scanning
O
signal 2
Keypad column scanning
O
signal 1
Keypad column scanning
O
signal 0
IO Keypad grounding
O Hands-free speaker signal P
O Hands-free speaker signal N
13
Remarks