Theory of Operation
: Controller
3-57
3.2.6.4 Keypad
The Dual Display Model contains a 21 button keypad, which translates to a 5x5 row and column
keypad matrix as shown in
Figure 3-46
. The keypad also contains LEDs for the backlighting of the
keys, which is described in more detail in
Section 3.2.6.3: "Intelligent Lighting"
. Every key is assigned
a particular row and column to identify the unique key, as shown in keypad mapping
Table 3-8
. The
keypad flex 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.
Figure 3-46.
Keypad Interface Outline
Table 3-8. Key Map Matrix
Key
Row, Column Map
Key
Row, Column Map
{
0 , 4
3
3 , 2
|
1 , 4
4
2 , 0
}
2 , 4
5
2 , 1
H
4 , 0
6
2 , 2
<
4 , 1
7
1 , 0
U
0 , 3
8
1 , 1
D
4 , 2
9
1 , 2
>
1 , 3
*
0 , 0
P
2 , 3
0
0 , 1
*FPC = Flexible Printed Circuit
OMAP
ROW
COLUMN
KEYPAD FPC
Summary of Contents for ASTRO APX 7000
Page 1: ......
Page 4: ...iv Document History Notes ...
Page 24: ...2 4 Radio Power DC Power Routing VOCON Board Notes ...
Page 98: ...3 74 Theory of Operation Global Positioning System GPS ...
Page 163: ...Troubleshooting Charts PA Failure 5 59 ...
Page 164: ...5 60 Troubleshooting Charts PA Failure ...
Page 276: ...7 58 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 318: ...8 42 Schematics Boards Overlays and Parts Lists Transceiver RF Boards VHF 700 800 Notes ...
Page 380: ...8 104 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF1 700 800 MHz Notes ...
Page 432: ...8 156 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF1 VHF Notes ...
Page 458: ...8 182 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF1 UHF2 Notes ...
Page 498: ...8 222 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 700 800 MHz Notes ...
Page 546: ...8 270 Schematics Boards Overlays and Parts Lists Transceiver RF Boards UHF2 VHF Notes ...
Page 606: ...8 330 Schematics Boards Overlays and Parts Lists VOCON Boards Notes ...
Page 638: ...Glossary 10 Glossary Notes ...
Page 643: ......