Motorola CML12S-DP256 Busport, Keypad / Port H, PCOM1 and PCOM2, connected and 7,8 connected

C M L 1 2 S D P 2 5 6

BUS_PORT

GND	1	2
PA2/D10	3	4
PA1/D9	5	6
PA0/D8	7	8
A0	9	10
A1	11	12
A10	13	14
OE*	15	16
A11	17	18
A9	19	20
A8	21	22
A12	23	24
WE*	25	26
PE3/LSTRB*	27	28
PE5/MODA	29	30
PE6/MODB	31	32
+5V	33	34
PE2/RW	35	36
PE4/ECLK	37	38
GND	39	40

D11/PA3

D12/PA4

D13/PA5

D14/PA6

D15/PA7

A2

A3

A4

A5

A6

A7

A13

A14

A15 PE7/NOACC ** PE1/IRQ* PE0/ XIRQ*

RESERVED RESERVED RESET*

0 7 / 1 7 / 0 2

The BUS_PORT supports off-board memory devices while the HCS12 is in expanded mode.

PA0/D8 - PA7/D15 High Byte Data Bus in Wide Expanded Mode. Port A in Single Chip Mode.

A0 – A15 Latched Memory Addresses 0 to 15.

OE* Memory Output Enable signal, Active Low. Valid with ECLK and R/W high.

WE* Memory Write Enable signal, Active Low. Valid with ECLK high and R/W low.

RESET* HCS12 active low RESET signal.

KEYPAD / PORT H

The KEYPAD / PORT H connector provides interface for the HCS12 port H or applying a keypad such as the Axiom Mfg. HC-KP. When applied as a KEYPAD connector, the interface is for a passive 4 x 4 matrix (16 key) keypad device.

1

2

3

4

5

6

7

8

PH0

PH1

PH2

PH3

PH4

PH5

PH6

PH7

This interface is implemented as a software key scan. Pins PH0-3 are used as column drivers which are active high outputs. Pins PH4-7 are used for row input and will read high when their row is high.

See the file Key12Dx.ASM for an example program using this connector.

P_COM1 and P_COM2

1

TXD0

RXD0

4 GND

16 The COM-1port has a Female DB9 connector that interfaces to

26 7 the HCS12 internal SCI0 serial port via the U11 RS232

37 8 transceiver. It uses a simple 2 wire asynchronous serial

48 9 interface and is translated to RS232 signaling levels.

5 9 X 1,4,6 connected and 7,8 connected

17