HC705RC17GRSSLASHD datasheet(22/126 Pages) NXP

22 / 126 page

General Description

General Release Specification

MC68HC705RC17 — Rev. 2.0

General Description

1.5.6 IRO

The IRO pin is the high-current source and sink output of the carrier

modulator transmitter subsystem which is suitable for driving infrared

(IR) LED biasing logic. See Section 9. Carrier Modulator Transmitter

(CMT).

1.5.7 Port A (PA0–PA7)

These eight I/O lines comprise port A. The state of any pin is software

programmable and all port A lines are configured as inputs during

power-on or reset. For detailed information on I/O programming, see

Section 7. Parallel Input/Output (I/O).

1.5.8 Port B (PB0–PB7)

These eight I/O lines comprise port B. The state of any pin is software

programmable and all port B lines are configured as inputs during

power-on or reset. Each port B I/O line has a mask optionable pullup for

keyscan. For detailed information on I/O programming, see Section 7.

Parallel Input/Output (I/O).

1.5.9 Port C (PC0–PC1 and PC4–PC7)

These six I/O lines comprise port C. PC0 is a high-current pin. PC4

through PC7 are available only in higher pin count (>28) packages. The

state of any pin is software programmable and all port C lines are

configured as input during power-on or reset. For detailed information on

I/O programming, see Section 7. Parallel Input/Output (I/O).

NOTE:

Only two bits of port C are bonded out in 28-pin packages for the

MC68HC705RC17, although port C is truly a 6-bit port. Since pins

PC4–PC7 are unbonded, software should include the code to set their

respective data direction register locations to outputs to avoid floating

inputs.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

HC705RC17GRS/D Datasheet(PDF) 22 Page - NXP Semiconductors