MC68HC708MP16 Datasheet, PDF (300/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

Serial Communications Interface Module (SCI)
14.7 I/O Signals
Port F shares two of its pins with the SCI module. The two SCI I/O pins
are:
• PTF5/TxD — Transmit data
• PTF4/RxD — Receive data
14.7.1 PTF5/TxD (Transmit Data)
The PTF5/TxD pin is the serial data output from the SCI transmitter. The
SCI shares the PTF5/TxD pin with port F. When the SCI is enabled, the
PTF5/TxD pin is an output regardless of the state of the DDRF5 bit in
data direction register F (DDRF).
14.7.2 PTF4/RxD (Receive Data)
The PTF4/RxD pin is the serial data input to the SCI receiver. The SCI
shares the PTF4/RxD pin with port F. When the SCI is enabled, the
PTF4/RxD pin is an input regardless of the state of the DDRF4 bit in data
direction register F (DDRF).
14.8 I/O Registers
The following I/O registers control and monitor SCI operation:
• SCI control register 1 (SCC1)
• SCI control register 2 (SCC2)
• SCI control register 3 (SCC3)
• SCI status register 1 (SCS1)
• SCI status register 2 (SCS2)
• SCI data register (SCDR)
• SCI baud rate register (SCBR)
Technical Data
300
MC68HC708MP16 — Rev. 3.1
Serial Communications Interface Module (SCI)
Freescale Semiconductor