Keypad And Display Module; Table 1. Option Select Functions - Motorola ASTRO Digital Saber Service Manual

Keypad and Display
Module
Most of the signals are extensions of circuits described in other areas
of this manual. However there are two option select pins used to
configure special modes; Option Select 1 and Option Select 2. These
pins are controlled by accessories connected to the universal
connector. The following table outlines their functions as defined at
the universal connector:
Table 1 . Option Select Functions
Keyload
No Function
External PTT
The front cover assembly contains the internal speaker, and internal
microphone. An optional integral 2 line by 14 character LCD display
is available with either a 3 x 2 keypad or 3 x 6 keypad. This unit is not
considered field repairable.
The internal speaker and microphone are connected to the VOCON
connector J701 through a flex circuit. This flex circuit along with J701
also contain the keypad control lines. The keypad is read though a row
and column matrix made up of ROW1, ROW2, ROW3, ROW4, ROW5,
ROW6, and COL1, COL2, and COL3. These signals are input to I/O
ports on the SLIC (U206) and individually pulled to a high state
through resistors. When a key is pressed the respective signals for a
single row and a single column are set to logic zero. The MCU reads
these ports through the SLIC parallel registers, provides for key
debounce, and determines which key has been pressed.
The display is controlled by the MCU which programs the display
through the SPI bus, DISP_EN* (select) and DISP_RST*. In addition
display backlighting is provided by two white LEDs controlled by the
BL_EN signal. SW_B+ routed to the display is used to power these
LEDs. All other circuitry on the display is powered by 5Vdc provided
by the VOCON board. The display is connected to the VOCON board
at J601 through a separate flex circuit.
Opt Sel 1
1
1
0
Opt Sel 2
0
1
1
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