MC68HC908AP16CFB datasheet(270/440 Pages) MOTOROLA

270 / 440 page

Infrared Serial Communications

Data Sheet

MC68HC908AP Family — Rev. 2.5

270

MOTOROLA

To protect status bits during the break state, write a logic 0 to the BCFE

bit. With BCFE at logic 0 (its default state), software can read and write

I/O registers during the break state without affecting status bits. Some

status bits have a two-step read/write clearing procedure. If software

does the first step on such a bit before the break, the bit cannot change

during the break state as long as BCFE is at logic 0. After the break,

doing the second step clears the status bit.

14.9 I/O Signals

The two IRSCI I/O pins are:

•

PTC6/SCTxD — Transmit data

•

PTC7/SCRxD — Receive data

14.9.1 PTC6/SCTxD (Transmit Data)

The PTC6/SCTxD pin is the serial data (standard or infrared) output from

the SCI transmitter. The IRSCI shares the PTC6/SCTxD pin with port C.

When the IRSCI is enabled, the PTC6/SCTxD pin is an output

regardless of the state of the DDRC6 bit in data direction register C

(DDRC).

NOTE:

The PTC6/SCTxD pin is an open-drain pin when configured as an

output. Therefore, when configured as SCTxD or a general purpose

output pin (PTC6), a pullup resistor must be connected to this pin.

14.9.2 PTC7/SCRxD (Receive Data)

The PTC7/SCRxD pin is the serial data input to the IRSCI receiver. The

IRSCI shares the PTC7/SCRxD pin with port C. When the IRSCI is

enabled, the PTC7/SCRxD pin is an input regardless of the state of the

DDRC7 bit in data direction register C (DDRC).

NOTE:

The PTC7/SCRxD pin is an open-drain pin when configured as an

output. Therefore, when configured as a general purpose output pin

(PTC7), a pullup resistor must be connected to this pin.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

MC68HC908AP16CFB Datasheet(PDF) 270 Page - Motorola, Inc