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MC68H(R)C908JL3E/JK3E/JK1E
—
Rev. 2.0
Technical Data
MOTOROLA
Input/Output (I/O) Ports
153
Technical Data – MC68H(R)C908JL3E/JK3E/JK1E
Section 12. Input/Output (I/O) Ports
12.1 Contents
12.2
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153
12.3
12.3.1
12.3.2
12.3.3
Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156
Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . .156
Data Direction Register A (DDRA). . . . . . . . . . . . . . . . . . .157
Port A Input Pull-up Enable Register (PTAPUE) . . . . . . . .158
12.4
12.4.1
12.4.2
Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . .159
Data Direction Register B (DDRB). . . . . . . . . . . . . . . . . . .160
12.5
12.5.1
12.5.2
12.5.3
Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161
Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . .162
Data Direction Register D (DDRD). . . . . . . . . . . . . . . . . . .163
Port D Control Register (PDCR). . . . . . . . . . . . . . . . . . . . .164
12.2 Introduction
Twenty three (23) bidirectional input-output (I/O) pins form three parallel
ports. All I/O pins are programmable as inputs or outputs.
NOTE:
Connect any unused I/O pins to an appropriate logic level, either V
DD
or
V
SS
. Although the I/O ports do not require termination for proper
operation, termination reduces excess current consumption and the
possibility of electrostatic damage.