Microchip Technology MA330025-1 Data Sheet
2009-2012 Microchip Technology Inc.
DS70616G-page 357
dsPIC33EPXXX(GP/MC/MU)806/810/814 and PIC24EPXXX(GP/GU)810/814
REGISTER 20-2:
U
x
STA: UART
x
STATUS AND CONTROL REGISTER
R/W-0
R/W-0
R/W-0
U-0
R/W-0, HC
R/W-0
R-0
R-1
UTXISEL1
UTXINV
UTXISEL0
—
UTXBRK
UTXEN
UTXBF
TRMT
bit 15
bit 8
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
Legend:
HC = Hardware Clearable bit
C = Clearable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 15,13
UTXISEL<1:0>: UARTx Transmission Interrupt Mode Selection bits
11 = Reserved; do not use
10 = Interrupt when a character is transferred to the Transmit Shift Register (TSR) and as a result, the
11 = Reserved; do not use
10 = Interrupt when a character is transferred to the Transmit Shift Register (TSR) and as a result, the
transmit buffer becomes empty
01 = Interrupt when the last character is shifted out of the Transmit Shift Register; all transmit
operations are completed
00 = Interrupt when a character is transferred to the Transmit Shift Register (this implies there is at
least one character open in the transmit buffer)
bit 14
UTXINV: UARTx Transmit Polarity Inversion bit
If IREN = 0:
1 = UxTX Idle state is ‘0’
0 = UxTX Idle state is ‘1’
If IREN = 1:
1 = IrDA encoded, UxTX Idle state is ‘1’
0 = IrDA encoded, UxTX Idle state is ‘0’
If IREN = 0:
1 = UxTX Idle state is ‘0’
0 = UxTX Idle state is ‘1’
If IREN = 1:
1 = IrDA encoded, UxTX Idle state is ‘1’
0 = IrDA encoded, UxTX Idle state is ‘0’
bit 12
Unimplemented: Read as ‘0’
bit 11
UTXBRK: UARTx Transmit Break bit
1 = Sends Sync Break on next transmission – Start bit, followed by twelve ‘0’ bits, followed by Stop bit;
1 = Sends Sync Break on next transmission – Start bit, followed by twelve ‘0’ bits, followed by Stop bit;
cleared by hardware upon completion
0 = Sync Break transmission is disabled or completed
bit 10
UTXEN: UARTx Transmit Enable bit
1 = Transmit is enabled, UxTX pin is controlled by UARTx
0 = Transmit is disabled, any pending transmission is aborted and the buffer is reset; UxTX pin
0 = Transmit is disabled, any pending transmission is aborted and the buffer is reset; UxTX pin
controlled by port
bit 9
UTXBF: UARTx Transmit Buffer Full Status bit (read-only)
1 = Transmit buffer is full
0 = Transmit buffer is not full, at least one more character can be written
1 = Transmit buffer is full
0 = Transmit buffer is not full, at least one more character can be written
bit 8
TRMT: Transmit Shift Register 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
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
bit 7-6
URXISEL<1:0>: UARTx Receive Interrupt Mode Selection bits
11 = Interrupt is set on UxRSR transfer making the receive buffer full (i.e., has 4 data characters)
10 = Interrupt is set on UxRSR transfer making the receive buffer 3/4 full (i.e., has 3 data characters)
0x = Interrupt is set when any character is received and transferred from the UxRSR to the receive
11 = Interrupt is set on UxRSR transfer making the receive buffer full (i.e., has 4 data characters)
10 = Interrupt is set on UxRSR transfer making the receive buffer 3/4 full (i.e., has 3 data characters)
0x = Interrupt is set when any character is received and transferred from the UxRSR to the receive
buffer; receive buffer has one or more characters
Note 1: Refer to Section 17. “UART” (DS70582) in the “dsPIC33E/PIC24E Family Reference Manual” for
information on enabling the UARTx module for transmit operation.