dsPIC30F Family Reference Manual
DS70066C-page 19-4 © 2004 Microchip Technology Inc.
Register 19-2: UXSTA: UARTX Status and Control Register
Upper Byte:
R/W-0 U-0 U-0 U-0 R/W-0 R/W-0 R-0 R-1
UTXISEL
— — — UTXBRK UTXEN UTXBF TRMT
bit 15 bit 8
Lower Byte:
R/W-0 R/W-0 R/W-0 R-1 R-0 R-0 R/C-0 R-0
URXISEL<1:0> ADDEN RIDLE PERR FERR OERR URXDA
bit 7 bit 0
bit 15 UTXISEL: Transmission Interrupt Mode Selection bit
1 = Interrupt when a character is transferred to the Transmit Shift register and as result, the transmit buffer
becomes empty
0 = Interrupt when a character is transferred to the Transmit Shift register (this implies that there is at least
one character open in the transmit buffer)
bit 14-12 Unimplemented: Read as ‘0’
bit 11 UTXBRK: Transmit Break bit
1 = UxTX pin is driven low, regardless of transmitter state
0 = UxTX pin operates normally
bit 10 UTXEN: Transmit Enable bit
1 = UART transmitter enabled, UxTX pin controlled by UART (if UARTEN = 1)
0 = UART transmitter disabled, any pending transmission is aborted and buffer is reset. UxTX pin controlled
by PORT.
bit 9 UTXBF: Transmit Buffer Full Status bit (Read Only)
1 = Transmit buffer is full
0 = Transmit buffer is not full, at least one more data word can be written
bit 8 TRMT: Transmit Shift Register is Empty bit (Read Only)
1 = Transmit shift register is empty and transmit buffer is empty (the last transmission has completed)
0 = Transmit shift register is not empty, a transmission is in progress or queued in the transmit buffer
bit 7-6 URXISEL<1:0>: Receive Interrupt Mode Selection bit
11 =Interrupt flag bit is set when Receive Buffer is full (i.e., has 4 data characters)
10 =Interrupt flag bit is set when Receive Buffer is 3/4 full (i.e., has 3 data characters)
0x =Interrupt flag bit is set when a character is received
bit 5 ADDEN: Address Character Detect (bit 8 of received data = 1)
1 = Address Detect mode enabled. If 9-bit mode is not selected, this control bit has no effect.
0 = Address Detect mode disabled
bit 4 RIDLE: Receiver Idle bit (Read Only)
1 = Receiver is Idle
0 = Data is being received
bit 3 PERR: Parity Error Status bit (Read Only)
1 = Parity error has been detected for the current character
0 = Parity error has not been detected
bit 2 FERR: Framing Error Status bit (Read Only)
1 = Framing Error has been detected for the current character
0 = Framing Error has not been detected
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