Ports And Connectors; Lcd_Port; Keypad - Motorola 68HC12B32 User Manual

PORTS AND CONNECTORS

LCD_PORT

The LCD_PORT interface is connected to the data bus and memory mapped to locations 270
– 27F hex assigned to CS7. For the standard display, address 270 is the Command register,
address 271 is the Data register.
The interface supports all OPTREX
characters and provides the most common pinout for a dual row rear mounted display
connector. Power, ground, and Vee are also available at the LCDPORT-1 connector.
+5V 2 1 GND
A0 4 3 LCD-Vee
LCD1 6 5 /RW
D9 8 7 D8
D11 10 9 D10
D13 12 11 D12
D15 14 13 D14
LCD3 2 LCD2
1
4 3 LCD4

KEYPAD

1 PS4 The KEYPAD connector is a passive 8-pin connector that can be used to
connect a 4 x 4 matrix (16 key) keypad device. The connector is mapped to
2 PS5
the HC12 I/O ports S and P. This interface is implemented as a software
3 PS6
keyscan. Pins PS4-7 are used as column drivers which are active low
4 PS7
outputs. Pins PP4-7 are used for row input and provide an idle hi condition
5 PP4
with internal pull-ups to provide active key detection under software control.
6 PP5
7 PP6
8 PP7
See the HC12 Technical Reference Manual for a full description of these pins and the file
KEYLCD12.ASM for an example program using this connector.
DMC series displays in 8 bit bus mode with up to 80
LCD-Vee is supplied by U13 and is adjusted by the R18
Potentiometer (adjustable resistor).
See the file KEYLCD12.ASM for an example program using this
LCD connector.
Additional lines can be used as enables for larger panels and
are mapped as:
LCD2 = $274 & $275
LCD3 = $278 & $279
Command Register:$270
Data Register:
LCD4 = $27C & $27D
11
$271