MC68HC05C8A Datasheet, PDF (47/116 Pages) Motorola, Inc – Microcontrollers

Chapter 9
Serial Communications Interface (SCI)
9.1 Introduction
The serial communications interface (SCI) module allows high-speed asynchronous communication with
peripheral devices and other microcontroller units (MCU).
9.2 Features
Features of the SCI module include:
• Standard mark/space non-return-to-zero format
• Full duplex operation
• 32 programmable baud rates
• Programmable 8-bit or 9-bit character length
• Separately enabled transmitter and receiver
• Two receiver wakeup methods:
– Idle line wakeup
– Address mark wakeup
• Interrupt-driven operation capability with five interrupt flags:
– Transmitter data register empty
– Transmission complete
– Receiver data register full
– Receiver overrun
– Idle receiver input
• Receiver framing error detection
• 1/16 bit-time noise detection
9.3 SCI Data Format
The SCI uses the standard non-return-to-zero mark/space data format illustrated in Figure 9-1.
8-BIT DATA FORMAT
(BIT M IN SCCR1 CLEAR)
NEXT
START
BIT
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
STOP
BIT
START
BIT
9-BIT DATA FORMAT
(BIT M IN SCCR1 SET)
NEXT
START
BIT ^{BIT 0}
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
STOP ^START
BIT
BIT
Figure 9-1. SCI Data Format
MC68HC05C8A • MC68HCL05C8A • MC68HSC05C8A Data Sheet, Rev. 5.1
Freescale Semiconductor
47