PIC16C745/P Microchip Technology, PIC16C745/P Datasheet - Page 75

• Manufacturer Part Number: PIC16C745/P
• Description: 8-Bit CMOS Microcontrollers with USB
• Manufacturer: Microchip Technology

11.0
The Universal Synchronous Asynchronous Receiver
Transmitter (USART) module is one of the two serial I/
O modules. (USART is also known as a Serial Commu-
nications Interface or SCI). The USART can be config-
ured as a full duplex asynchronous system that can
communicate with peripheral devices, such as CRT ter-
minals and personal computers, or it can be configured
REGISTER 11-1: TRANSMIT STATUS AND CONTROL REGISTER (TXSTA: 98h)
1999 Microchip Technology Inc.
bit7
bit 7:
bit 6:
bit 5:
bit 4:
bit 3:
bit 2:
bit 1:
bit 0:
R/W-0
CSRC
UNIVERSAL SYNCHRONOUS
ASYNCHRONOUS RECEIVER
TRANSMITTER (USART)
CSRC: Clock Source Select bit
Asynchronous mode
Don’t care
Synchronous mode
1 = Master mode (Clock generated internally from BRG)
0 = Slave mode (Clock from external source)
TX9: 9-bit Transmit Enable bit
1 = Selects 9-bit transmission
0 = Selects 8-bit transmission
TXEN: Transmit Enable bit
1 = Transmit enabled
0 = Transmit disabled
Note: SREN/CREN overrides TXEN in SYNC mode.
SYNC: USART Mode Select bit
1 = Synchronous mode
0 = Asynchronous mode
Unimplemented: Read as '0'
BRGH: High Baud Rate Select bit
Asynchronous mode
1 = High speed
0 = Low speed
Synchronous mode
Unused in this mode
TRMT: Transmit Shift Register Status bit
1 = TSR empty
0 = TSR full
TX9D: 9th bit of transmit data. (Can be used for parity.)
R/W-0
TX9
R/W-0
TXEN
R/W-0
SYNC
Advanced Information
U-0
—
BRGH
R/W-0
as a half duplex synchronous system that can commu-
nicate with peripheral devices, such as A/D or D/A inte-
grated circuits, Serial EEPROMs etc.
The USART can be configured in the following modes:
• Asynchronous (full duplex)
• Synchronous - Master (half duplex)
• Synchronous - Slave (half duplex)
Bits SPEN (RCSTA<7>) and TRISC<7:6> have to be
set in order to configure pins RC6/TX/CK and RC7/RX/
DT as the universal synchronous asynchronous
receiver transmitter.
TRMT
R-1
R/W-0
TX9D
PIC16C745/765
bit0
R = Readable bit
W = Writable bit
U = Unimplemented bit,
- n = Value at POR reset
read as ‘0’
DS41124A-page 75