3. TECHNICAL BRIEF
- 44 -
3.9 Keypad Switches and Scanning
The key switches are metal domes, which make contact between two concentric pads on the keypad
layer of the PCB when pressed. There are 27 switches (Normal Key 24EA, Camera side key, Volume
up down side key), connected in a matrix of 5 rows by 5 columns and additional GPIO 35 for
KEY_ROW5, as shown in Figure 3-24, except for the power switch (KB1), which is connected
independently. Functions, the row and column lines of the keypad are connected to ports of AD6527.
The columns are outputs, while the rows are inputs and have pull-up resistors built in.
When a key is pressed, the corresponding row and column are connected together, causing the row
input to go low and generate an interrupt. The columns/rows are then scanned by AD6527 to identify
the pressed key.
4
CAMERA
2
T
UP
#
3
CLR
0
DOWN
END
RIGHT
FAV
1
6
5
7
LEFT
SEL
9
VOL_UP
VOL_DOWN
8
*
MENU
SEND
CONF
R345
680
R344
R343
680
680
SW323
SW306
SW327
SW305
680
R342
100
R306
SW322
SW300
SW304
SW301
SW309
VA300
ECVAS1005-14A30-120NBT
ECVAS1005-14A30-120NBT
VA303
SW319
SW317
680
R316
SW307
SW321
SW320
SW315
680
R338
680
R335
680
R330
SW303
SW302
SW308
SW312
SW326
SW310
680
R346
VA301
ECVAS1005-14A30-120NBT
SW311
R305
100
10K
R301
SW316
SW324
ECVAS1005-14A30-120NBT
VA304
R303
100
SW328
VBAT
R324
680
100
R307
SW318
SW313
680
R302
ECVAS1005-14A30-120NBT
VA302
ECVAS1005-14A30-120NBT
VA308
SW325
VA307
ECVAS1005-14A30-120NBT
680
SW314
R340
R304
100
KEY_ROW2
KEY_ROW5
KEY_COL1
KEY_COL0
KEY_COL4
KEY_ROW1
KEY_COL3
KEY_ROW3
KEY_ROW4
KEY_COL2
KEY_ROW0
POWERKEY
Figure 3-27. Keypad Switches and Scanning
Содержание C3380
Страница 1: ...Service Manual Model C3380 Date November 2005 Issue 1 0 Service Manual C3380 ...
Страница 3: ... 4 ...
Страница 83: ...4 TROUBLE SHOOTING 84 4 11 KEY backlight Trouble Test Points Figure 4 22 ...
Страница 98: ...4 TROUBLE SHOOTING 99 Yes No Yes No Replace M201 Establish a call Replace U101 Software Re_download ...
Страница 109: ...Note 110 ...
Страница 116: ... 117 8 PCB LAYOUT ...
Страница 117: ... 118 8 PCB LAYOUT ...
Страница 125: ...10 STAND ALONE TEST 126 Figure 10 2 HW test setting Figure 10 3 Ramping profile ...
Страница 129: ... 130 ...
Страница 131: ... 132 ...