MC68HC05L16 Datasheet, PDF (51/146 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6
Parallel Input/Output (I/O)
6.1 Introduction
The MCU has five parallel ports:
• Port A has eight I/O pins.
• Port B has eight input/only pins.
• Port C has eight I/O pins.
• Port D has seven output-only pins.
• Port E has eight output-only pins.
Most of these 39 I/O pins serve multiple purposes depending on the configuration of the MCU system.
The configuration is in turn controlled by hardware mode selection as well as internal control registers.
DATA DIRECTION
REGISTER BIT
LATCHED OUTPUT
DATA BIT
I/O
OUTPUT
PIN
INPUT
REG
BIT
INPUT
I/O
Figure 6-1. Port I/O Circuitry for One Bit
MC68HC05L16 • MC68HC705L16 Data Sheet, Rev. 4.1
Freescale Semiconductor
51