Intel 8XC196MC User Manual
8XC196MC, MD, MH USER’S MANUAL
6-2
6.2
INPUT-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.
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.)
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)
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.
ter.
Table 6-2. Standard Input-only Port Pins
Port Pin
Special-function
Signal(s)
Special-function
Signal Type
Associated
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)
—
—
—