Intel 8XC196MC, 8XC196MD, 8XC196MH INPUT-ONLY Ports 1 MC, MD only, Standard Input-only Port Pins

8XC196MC, MD, MH USER’S MANUAL

6.2INPUT-ONLY PORTS 1 (MC, MD ONLY) AND 0

Port 0 is an eight-bit, high-impedance, input-only port that provides analog and digital inputs. The input-only pins can be read as digital inputs; most of them are also inputs to the A/D converter. The input-only ports differ from the other standard ports in that their pins can be used only as in- puts to the digital or analog circuitry. On the 8XC196MC and 8XC196MD, port 1 is an input-only port that serves the same purpose as port 0. The 8XC196MC implements five pins, while the 8XC196MD implements all eight.

8XC196MH: On the 8XC196MH, port 1 is a standard bidirectional port that shares pins with the serial I/O port. (See “Bidirectional Ports 1 (MH Only), 2, 5, and 7 (MD Only)” on page 6-4.)

Because port 0 (and port 1 of the 8XC196MC, MD) is permanently configured as an input-only port, it has no configuration registers. Its single register, Px_PIN, can be read to determine the current state of the pin. The register is byte-addressable and can be windowed. (See “Windowing” on page 5-16)

Table 6-2 lists the standard input-only port pins and Table 6-3 describes the Px_PIN status regis- ter.

Table 6-2. Standard Input-only Port Pins

	Port Pin	Special-function	Special-function		Associated
		Signal(s)	Signal Type		Peripheral
P0.5:0		ACH5:0	Input		A/D converter
P0.6		ACH6	Input		A/D converter
		T1CLK (MH)	Input		EPA
P0.7		ACH7	Input		A/D converter
		T1DIR (MH)	Input		EPA
P1.0	(MC, MD)	ACH8	Input		A/D converter
P1.1	(MC, MD)	ACH9	Input		A/D converter
P1.2	(MC, MD)	ACH10	Input		A/D converter
		T1CLK	Input		EPA
P1.3	(MC, MD)	ACH11	Input		A/D converter
		T1DIR	Input		EPA
P1.4	(MC, MD)	ACH12	Input		A/D converter
P1.5	(MD)	ACH13	Input		A/D converter
P1.6	(MD)	—	—	—
P1.7	(MD)	—	—	—

6-2