MC68HC05C8A Datasheet, PDF (55/158 Pages) Motorola, Inc – Microcontrollers

Technical Data — MC68HC05C8A • MC68HCL05C8A • MC68HSC05C8A
Section 7. Input/Output (I/O) Ports
7.1 Contents
7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
7.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
7.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
7.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
7.7 Input/Output Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
7.2 Introduction
The MC68HC05C8A has three 8-bit input/output (I/O) ports.These 24
port pins are programmable as either inputs or outputs under software
control of the data direction registers. Port D does not have a data
direction register, and its seven pins are input only with the exception of
certain serial communications (SCI)/serial peripheral interface (SPI)
functions.
NOTE: To avoid a glitch on the output pins, write data to the I/O port data
register before writing a 1 to the corresponding data direction register.
MC68HC05C8A • MC68HCL05C8A • MC68HSC05C8A — Rev. 5.0
MOTOROLA
Input/Output (I/O) Ports
Technical Data
55