MC908AB32CFUE Datasheet, PDF (242/392 Pages) Freescale Semiconductor, Inc – Microcontrollers

Serial Communications Interface
15.4 Pin Name Conventions
The generic names of the SCI I/O pins are:
• RxD (receive data)
• TxD (transmit data)
SCI I/O (input/output) lines are implemented by sharing parallel I/O port
pins. The full name of an SCI input or output reflects the name of the
shared port pin. Table 15-1 shows the full names and the generic names
of the SCI I/O pins.
The generic pin names appear in the text of this section.
Table 15-1. Pin Name Conventions
Generic Pin Names:
RxD
Full Pin Names:
PTE1/RxD
TxD
PTE0/TxD
15.5 Functional Description
Figure 15-1 shows the structure of the SCI module. The SCI allows full-
duplex, asynchronous, NRZ serial communication among the MCU and
remote devices, including other MCUs. The transmitter and receiver of
the SCI operate independently, although they use the same baud rate
generator. During normal operation, the CPU monitors the status of the
SCI, writes the data to be transmitted, and processes received data.
Technical Data
242
MC68HC908AB32 — Rev. 1.1
Serial Communications Interface Module (SCI)
Freescale Semiconductor