st92f124 STMicroelectronics, st92f124 Datasheet - Page 236

• Manufacturer Part Number: st92f124
• Description: 8/16-bit Single Voltage Flash Mcu Family With Ram, E3 Tmemulated Eeprom, Can 2.0b And J1850 Blpd
• Manufacturer: STMicroelectronics

ASYNCHRONOUS SERIAL COMMUNICATIONS INTERFACE (SCI-A)
10.6 ASYNCHRONOUS SERIAL COMMUNICATIONS INTERFACE (SCI-A)
10.6.1 Introduction
The Asynchronous Serial Communications Inter-
face (SCI-A) offers a flexible means of full-duplex
data exchange with external equipment requiring
an industry standard NRZ asynchronous serial
data format. The SCI-A offers a very wide range of
baud rates using two baud rate generator sys-
tems.
10.6.2 Main Features
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– Address bit (MSB)
– Idle line
– Overrun error
– Noise error
– Frame error
– Transmit data register empty
– Transmission complete
– Receive data register full
– Idle line received
– Overrun error detected
– Transmits parity bit
– Checks parity of received data byte
Full duplex, asynchronous communications
NRZ standard format (Mark/Space)
Dual baud rate generator systems
Independently programmable transmit and
receive baud rates up to 700K baud.
Programmable data word length (8 or 9 bits)
Receive buffer full, Transmit buffer empty and
End of Transmission flags
Two receiver wake-up modes:
Muting
configurations
Separate enable bits for Transmitter and
Receiver
Three error detection flags:
Five interrupt sources with flags:
Parity control:
Reduced power consumption mode
LIN Master: 13-bit LIN Synch Break generation
capability
function
for
multiprocessor
10.6.3 General Description
The interface is externally connected to another
device by two pins (see
Through these pins, serial data is transmitted and
received as frames comprising:
This interface uses two types of baud rate genera-
tors:
– TDO: Transmit Data Output. When the trans-
– RDI: Receive Data Input is the serial data in-
– An Idle Line prior to transmission or reception
– A start bit
– A data word (8 or 9 bits) least significant bit
– A Stop bit indicating that the frame is com-
– A conventional type for commonly-used baud
– An extended type with a prescaler offering a
mitter is disabled, the output pin is in high im-
pedance. When the transmitter is enabled and
nothing is to be transmitted, the TDO pin is at
high level.
put. Oversampling techniques are used for
data recovery by discriminating between valid
incoming data and noise.
first
plete.
rates,
very wide range of baud rates even with non-
standard oscillator frequencies.
Figure
118):