MC68HC908KX2 MOTOROLA [Motorola, Inc], MC68HC908KX2 Datasheet - Page 197

• Manufacturer Part Number: MC68HC908KX2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

14.7 I/O Signals
14.7.1 TxD (Transmit Data)
14.7.2 RxD (Receive Data)
14.8 I/O Registers
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
Port B shares two of its pins with the SCI module. The two SCI I/O pins
are:
The TxD pin is the serial data output from the SCI transmitter. The SCI
shares the TxD pin with port B. When the SCI is enabled, the TxD pin is
an output regardless of the state of the DDRB5 bit in data direction
register B (DDRB).
The RxD pin is the serial data input to the SCI receiver. The SCI shares
the RxD pin with port B. When the SCI is enabled, the RxD pin is an input
regardless of the state of the DDRB4 bit in data direction register B
(DDRB).
These I/O registers control and monitor SCI operation:
•
•
•
•
•
•
•
•
•
Serial Communications Interface Module (SCI)
TxD — Transmit data
RxD — Receive data
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)
Serial Communications Interface Module (SCI)
Technical Data
I/O Signals
197