Datasheet

 2010-2012 Microchip Technology Inc. DS41417B-page 133
PIC16(L)F722A/723A
16.0 ADDRESSABLE UNIVERSAL
SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (AUSART)
The Addressable Universal Synchronous
Asynchronous Receiver Transmitter (AUSART)
module is a serial I/O communications peripheral. It
contains all the clock generators, shift registers and
data buffers necessary to perform an input or output
serial data transfer independent of device program
execution. The AUSART, also known as a Serial
Communications Interface (SCI), can be configured as
a full-duplex asynchronous system or half-duplex
synchronous system. Full-Duplex mode is useful for
communications with peripheral systems, such as CRT
terminals and personal computers. Half-Duplex
Synchronous mode is intended for communications
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs or other microcontrollers.
These devices typically do not have internal clocks for
baud rate generation and require the external clock
signal provided by a master synchronous device.
The AUSART module includes the following capabilities:
• Full-duplex asynchronous transmit and receive
• Two-character input buffer
• One-character output buffer
• Programmable 8-bit or 9-bit character length
• Address detection in 9-bit mode
• Input buffer overrun error detection
• Received character framing error detection
• Half-duplex synchronous master
• Half-duplex synchronous slave
• Sleep operation
Block diagrams of the AUSART transmitter and
receiver are shown in Figure 16-1 and Figure 16-2.
FIGURE 16-1: AUSART TRANSMIT BLOCK DIAGRAM
TXIF
TXIE
Interrupt
TXEN
TX9D
MSb
LSb
Data Bus
TXREG Register
Transmit Shift Register (TSR)
(8)
0
TX9
TRMT
SPEN
TX/CK
Pin Buffer
and Control
8
SPBRG
FOSC
÷ n
n
+ 1
Multiplier x4 x16 x64
SYNC 100
BRGH x10
Baud Rate Generator
•••