XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 204

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

Serial Interface
14.2 Serial Communication Interface (SCI)
14.2.1 Data Format
Data Sheet
204
The SCI on the MCU is an NRZ format (one start, eight or nine data, and one stop
bit) asynchronous communication system with independent internal baud rate
generation circuitry and an SCI transmitter and receiver. It can be configured for
eight or nine data bits (one of which may be designated as a parity bit, odd or even).
If enabled, parity is generated in hardware for transmitted and received data.
Receiver parity errors are flagged in hardware. The baud rate generator is based
on a modulus counter, allowing flexibility in choosing baud rates. There is a
receiver wakeup feature, an idle line detect feature, a loop-back mode, and various
error detection features. Two port pins provide the external interface for the
transmitted data (TXD) and the received data (RXD). See
The serial data format requires these conditions:
A frame consists of:
A BREAK is defined as the transmission or reception of a logic 0 for one frame or
more.
This SCI supports hardware parity for transmit and receive.
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An idle-line in the high state before transmission or reception of a message
A start bit (logic 0), transmitted or received, that indicates the start of each
character
Data that is transmitted or received least significant bit (LSB) first
A stop bit (logic 1) used to indicate the end of a frame
A start bit
A character of eight or nine data bits
A stop bit
Serial Interface
M68HC12B Family — Rev. 8.0
Figure
14-2.
MOTOROLA