Read Panasonic KX-DT521RU Service Manual online
13
KX-DT521RU/KX-DT521RU-B
4.2.8.
Key Circuit
The key detection is under the matrix control by IC205.
The HOOK key is independent from Key Scan Matrix and taken into the port singularly.
KEY Input control timing chart
KEYIN pins have a internal pull-down resistor.
KEYIN pins have a internal pull-down resistor.
If KEY is pushed, high level is latched by connecting STB(output high) and KEYIN. If not, low level is latched.
The value is fixed by reading twice.
The value is fixed by reading twice.
ASIC2
31
24
25
26
27
29
30
IC205
HOOK SW
1
2
C244
HOOK
2
15
14
13
12
11
10
28
KEYIN2
KEYIN0
LED_STB 6
LED_STB 4
LED_STB 5
LED_STB 3
LED_STB 2
LED_STB 2
LED_STB 0
LED_STB 1
LED_STB 7
KEYIN5
KEYIN4
KEYIN1
KEYIN3
*
1
2
FLASH/RECALL
1
2
9
1
2
MESSAGE
1
2
1
1
2
HOLD
1
2
REDIAL
1
2
0
1
2
7
1
2
#
1
2
5
1
2
INT’COM
1
2
3
1
2
CONF
1
2
8
1
2
6
1
2
TRANSFER
1
2
4
1
2
2
1
2
PROGRAM
1
2
SP-PHONE1
1
2
D235
D238
D239
D237
D236
D240
D241
RIGHT
1
2
LEFT
1
2
UP
1
2
DOWN
1
2
D242
AUTOANS/MUTE
1
2
CO5
1
2
CO4
1
2
CO3
1
2
CO2
1
2
CO1
1
2
CO8
1
2
CO7
1
2
CO6
1
2
AUTODIAL
1
2
once
twice
"7" is fixed.
"7"
"7" button is pressed.
When "LED_STB1" is high status
and the "7" button pressed,
the key-in information is read.
and the "7" button pressed,
the key-in information is read.
KEYIN1
(IC205 pin11)
(IC205 pin11)
KEY_CLK
(IC205 Internal)
(IC205 Internal)
LED_STB0
(IC205 pin24)
(IC205 pin24)
LED_STB1
(IC205 pin25)
(IC205 pin25)
LED_STB2
(IC205 pin26)
(IC205 pin26)
LED_STB3
(IC205 pin27)
(IC205 pin27)
LED_STB4
(IC205 pin28)
(IC205 pin28)
LED_STB5
(IC205 pin29)
(IC205 pin29)
LED_STB6
(IC205 pin30)
(IC205 pin30)
LED_STB7
(IC205 pin31)
(IC205 pin31)
Click on the first or last page to see other KX-DT521RU service manuals if exist.