MC68HC908KX8 Datasheet, PDF (149/310 Pages) Motorola, Inc – Microcontrollers

Technical Data — MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8
Section 10. Input/Output (I/O) Ports
10.1 Contents
10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
10.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
10.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
10.3.2 Data Direction Register A. . . . . . . . . . . . . . . . . . . . . . . . . . 152
10.3.3 Port A Input Pullup Enable Register. . . . . . . . . . . . . . . . . . 154
10.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
10.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
10.4.2 Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . 156
10.2 Introduction
Thirteen bidirectional input/output (I/O) pins form two parallel ports in the
16-pin plastic dual in-line package (PDIP) and small outline integrated
circuit (SOIC) package in the MC68HC908KX8 part. All I/O pins are
programmable as inputs or outputs. Port A has software selectable
pullup resistors if the port is used as a general-function input port.
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.
See Figure 10-1 for a summary of the I/O port registers.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
Input/Output (I/O) Ports
Technical Data
149