3. TECHNICAL BRIEF
- 40 -
3.8 Keypad Switches and Scanning
The key switches are metal domes, which make contact between two concentric pads on
thekeypad layer of the PCB when pressed. There are 21 switches (Normal Key 21EA, No
sidekey), connected in a matrix of 5 rows by 5 columns and additional GPIO 35 for KEY_ROW5,
as shown in Figure 3-27, except for the power switch, 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-upresistors 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.
Figure 3-27 Keypad Switches and Scanning
Y
E
K
SP301
SP315
SP310
2
0
3
3
R
0
8
6
SP300
R
L
C
SP313
0
8
6
0
4
3
R
0
8
6
5
3
3
R
P
R
A
H
S
D
N
E
9
8
T
H
G
I
R
SP316
0
D
N
E
S
1
8
0
3
A
V
0
5
0
2
0
S
4
1
C
L
V
A
L
E
S
1
0
3
R
K
0
1
SP309
SP304
0
5
0
2
0
S
4
1
C
L
V
A
7
0
3
A
V
6
0
3
A
V
0
5
0
2
0
S
4
1
C
L
V
A
5
P
U
R
A
T
S
SP317
SP306
SP303
SP312
SP311
0
8
6
2
4
3
R
0
5
0
2
0
S
4
1
C
L
V
A
9
0
3
A
V
0
8
6
9
3
3
R
0
8
6
1
4
3
R
0
5
0
2
0
S
4
1
C
L
V
A
3
0
3
A
V
2
0
3
A
V
0
5
0
2
0
S
4
1
C
L
V
A
U
N
E
M
0
8
6
3
4
3
R
0
5
0
2
0
S
4
1
C
L
V
A
1
1
3
A
V
SP318
0
8
6
0
1
3
R
SP307
SP320
SP314
0
5
0
2
0
S
4
1
C
L
V
A
0
3
3
A
V
SP302
6
3
0
1
3
A
V
0
5
0
2
0
S
4
1
C
L
V
A
4
4
0
3
A
V
0
5
0
2
0
S
4
1
C
L
V
A
7
1
3
R
0
8
6
0
8
6
4
2
3
R
9
0
3
R
0
8
6
7
SP305
SP308
0
5
0
2
0
S
4
1
C
L
V
A
1
3
3
A
V
SP319
T
F
E
L
N
W
O
D
0
5
0
2
0
S
4
1
C
L
V
A
5
0
3
A
V
T
A
B
V
A
T
A
D
_
M
I
S
4
L
O
C
_
Y
E
K
1
W
O
R
_
Y
E
K
3
L
O
C
_
Y
E
K
2
W
O
R
_
Y
E
K
3
W
O
R
_
Y
E
K
4
W
O
R
_
Y
E
K
2
L
O
C
_
Y
E
K
1
L
O
C
_
Y
E
K
0
L
O
C
_
Y
E
K
0
W
O
R
_
Y
E
K
Y
E
K
R
E
W
O
P
Содержание B2050
Страница 7: ... 6 2 PERFORMANCE 2 PERFORMANCE 2 1 H W Features ...
Страница 8: ... 7 2 PERFORMANCE ...
Страница 9: ... 8 2 PERFORMANCE 2 2 Technical Specification ...
Страница 10: ... 9 2 PERFORMANCE ...
Страница 11: ... 10 2 PERFORMANCE ...
Страница 12: ... 11 2 PERFORMANCE ...
Страница 13: ... 12 2 PERFORMANCE ...
Страница 53: ... 52 4 2 TX Trouble TEST POINT 13Mhz OSCILLATOR Mobile SW FEM TRANCEIVER LDO PAM 4 TROUBLE SHOOTING ...
Страница 57: ... 56 3 Checking Ant SW Mobile SW 4 TROUBLE SHOOTING ...
Страница 67: ... 66 TEST POINT 4 6 LCD Trouble 4 TROUBLE SHOOTING ...
Страница 70: ... 69 4 TROUBLE SHOOTING TEST POINT 4 7 Speaker Trouble ...
Страница 77: ... 76 4 TROUBLE SHOOTING 4 10 KEY backlight Trouble TEST POINT ...
Страница 91: ... 90 5 DOWNLOAD AND CALIBRATION 6 Press Start and Pover on the phone using JIG remote Power on Switch 1 ...
Страница 92: ...5 DOWNLOAD AND CALIBRATION 91 5 2 Calibration ...
Страница 93: ... 92 5 DOWNLOAD AND CALIBRATION ...
Страница 97: ......
Страница 103: ... 102 Figure 8 1 B2050 BOTTOM SIDE PCB LAYOUT 8 PCB LAYOUT ...
Страница 104: ... 103 8 PCB LAYOUT Figure 8 1 B2050 TOP SIDE PCB LAYOUT ...
Страница 105: ......
Страница 113: ...10 STAND ALONE TEST 112 ...
Страница 117: ......
Страница 119: ......
Страница 132: ... 131 ...
Страница 133: ... 132 ...