Figure 3-35. Lighting Controller Overview - Motorola APX 1000 Detailed Service Manual

3-46
OMAP
(12C) SCL
(12C) SDA
RST_OUT
3.2.6.4 Keypad
The Full Keypad Model contains a 21 button keypad, which translates to a 5x5 row and column
keypad matrix as shown in
keys, which is described in more detail in
a particular row and column to identify the unique key, as shown in keypad mapping
keypad board also contains 2, 6-channel filters that each row and column signal passes through.
Each row of the keypad contains an external pull-up resistor, and all the rows are interrupt based
inputs to OMAP. The columns are driven low by default in OMAP. When a key is pressed, the
corresponding key row and column are shorted together and causes a low level to be input on the
corresponding row in OMAP. Upon receiving the row interrupt, the OMAP IC is then programmed to
scan the column output to determine which corresponding column was selected that generated the
interrupt.
LED DRIVER
V_SW_5
(LP3943)
V-REG
VOUT PWR
LEVEL
SHIFT
SCL
SDA
RESET
A0
A1
A2

Figure 3-35. Lighting Controller Overview

Figure 3-36. The keypad also contains LEDs for the backlighting of the
LED0
LED1
LED2
LED3
LED4
LED5
LED6
LED8
LED9
LED10
LED11
Section 3.2.6.3: "Intelligent
Theory of Operation
J2301
KEYPAD WHITE
ILLUMINATION
J2302
R
STATUS
53
G
55
A
57
R
58
TX/RX
G
60
A
56
32
34 FRONT DISPLAY
WHITE BACKLIGHT
36
38
Lighting". Every key is assigned
Table
: Controller
3-7. The