Datasheet

PIC24FJ256GB110 FAMILY
DS39897C-page 204  2009 Microchip Technology Inc.
REGISTER 17-2: UxSTA: UARTx 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
(1)
UTXISEL0 — UTXBRK UTXEN
(2)
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
URXISEL1 URXISEL0 ADDEN RIDLE PERR FERR OERR URXDA
bit 7 bit 0
Legend: C = Clearable bit HC = Hardware 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>: 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 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: IrDA
®
Encoder Transmit Polarity Inversion bit
(1)
IREN = 0:
1 = UxTX Idle ‘0’
0 = UxTX Idle ‘1’
IREN =
1:
1 = UxTX Idle ‘1’
0 = UxTX Idle ‘0’
bit 12 Unimplemented: Read as ‘0’
bit 11 UTXBRK: Transmit Break bit
1 = Send 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 disabled or completed
bit 10 UTXEN: Transmit Enable bit
(2)
1 = Transmit enabled, UxTX pin controlled by UARTx
0 = Transmit 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 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
bit 7-6 URXISEL<1:0>: Receive Interrupt Mode Selection bits
11 = Interrupt is set on RSR transfer, making the receive buffer full (i.e., has 4 data characters)
10 = Interrupt is set on RSR 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 RSR to the receive buffer.
Receive buffer has one or more characters.
Note 1: Value of bit only affects the transmit properties of the module when the IrDA encoder is enabled
(IREN = 1).
2: If UARTEN = 1, the peripheral inputs and outputs must be configured to an available RPn pin.
See Section 10.4 “Peripheral Pin Select” for more information.