Chapter 12
Infrared Serial Communications Interface Module (IRSCI)
12.1 Introduction
The MC68HC908AP64 has two SCI modules:
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SCI1 is a standard SCI module, and
SCI2 is an infrared SCI module.
This section describes SCI2, the infrared serial communications interface (IRSCI) module which allows
high-speed asynchronous communications with peripheral devices and other MCUs. This IRSCI consists
of an SCI module for conventional SCI functions and a software programmable infrared encoder/decoder
sub-module for encoding/decoding the serial data for connection to infrared LEDs in remote control
applications.
NOTE
When the IRSCI is enabled, the SCTxD pin is an open-drain output and
requires a pullup resistor to be connected for proper SCI operation.
Features of the SCI module include the following:
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Full duplex operation
Standard mark/space non-return-to-zero (NRZ) format
Programmable 8-bit or 9-bit character length
Separately enabled transmitter and receiver
Separate receiver and transmitter CPU interrupt requests
Two receiver wakeup methods:
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Idle line wakeup
Address mark wakeup
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Interrupt-driven operation with eight interrupt flags:
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Transmitter empty
Transmission complete
Receiver full
Idle receiver input
Receiver overrun
Noise error
Framing error
Parity error
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Receiver framing error detection
Hardware parity checking
1/16 bit-time noise detection
Features of the infrared (IR) sub-module include the following:
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IR sub-module enable/disable for infrared SCI or conventional SCI on SCTxD and SCRxD pins
Software selectable infrared modulation/demodulation
(3/16, 1/16 or 1/32 width pulses)
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
181
FREESCALE [ Freescale ]
