Analog Port, COM1, COM2 | Motorola CMD912x, DG128, 68HC912D60, DT128

ANALOG PORT

PAD0	1	2	PAD8
PAD1	3	4	PAD9
PAD2	5	6	PAD10
PAD3	7	8	PAD11
PAD4	9	10	PAD12
PAD5	11	12	PAD13
PAD6	13	14	PAD14
PAD7	15	16	PAD15
VRL0	17	18	VRH0
VRL1	19	20	VRH1

The ANALOG port provides access to the Port AD0 and Port AD1 Analog-to-Digital input lines.

PAD0 – PAD7 HC12 Port AD0-15 is an input port or A/D Converter inputs.

VRH / VRL HC12 A/D Converter Reference Pins. See A/D Reference Section. To provide an external reference voltage, R3,4,10 and 32 may need to be removed. See schematic.

COM1

	1
TXD0	2	6
RXD0	3	7
	4	8
GND	5	9

The COM-1port has a Female DB9 connector that interfaces to the HC12 internal SCI0 serial port. It uses a simple 2 wire asynchronous serial interface and is translated to RS232 signaling levels.

COM2

TXD1

RXD1

GND

NOTE:

910

The COM-2has a Female DB9 connector that interfaces to the HC12 internal SCI1 serial port. It uses a simple 2 wire asynchronous serial interface and is translated to RS232 signaling levels.

JP1 may be used to reverse RS232 RX and TX signals to the COM2 connector.

1)COM1 and 2 connector Pins 1, 4, and 6 are connected for default handshake standards.

2)COM1 and 2 connector Pins 7 and 8 are connected for default handshake standards.

3)Handshake pins are provided access pads behind the COM connectors for user application and can be easily isolated from each other on the bottom of the CMD912x board.

4)SCI0:PS0/RXD0 and SCI1:PS2/RXD1 signals can be isolated from the RS232 transceiver by turning COM Switch positions 1 and 2 OFF respectfully.

5)SCI0:PS1/TXD0 and SCI1:PS3/TXD1 signals can be isolated from the RS232 transceiver by removing resistors R10 and R11 respectfully from the bottom of the CMD912x board.