PIC18F6585 Datasheet, PDF (287/496 Pages) Microchip Technology – 64/68/80-Pin High-Performance, 64-Kbyte Enhanced Flash Microcontrollers with ECAN Module

PIC18F6585/8585/6680/8680
23.2.2 DEDICATED CAN TRANSMIT
BUFFER REGISTERS
This section describes the dedicated CAN Transmit
Buffer registers and their associated control registers.
REGISTER 23-5: TXBnCON: TRANSMIT BUFFER n CONTROL REGISTERS [0 ≤ n ≤ 2]
U-0
R-0
R-0
R-0
R/W-0
U-0
R/W-0
Mode 0
—
TXABT TXLARB TXERR TXREQ
—
TXPRI1
R/W-0
TXPRI0
R/C-0
R-0
R-0
R-0
R/W-0
U-0
R/W-0 R/W-0
Mode 1, 2
TXBIF TXABT TXLARB TXERR TXREQ
—
TXPRI1 TXPRI0
bit 7
bit 0
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1-0
Mode 0:
Unimplemented: Read as ‘0’
Mode 1, 2:
TXBIF: Transmit Buffer Interrupt Flag bit
1 = Transmit buffer has completed transmission of message and may be reloaded
0 = Transmit buffer has not completed transmission of a message
TXABT: Transmission Aborted Status bit⁽¹⁾
1 = Message was aborted
0 = Message was not aborted
TXLARB: Transmission Lost Arbitration Status bit⁽¹⁾
1 = Message lost arbitration while being sent
0 = Message did not lose arbitration while being sent
TXERR: Transmission Error Detected Status bit⁽¹⁾
1 = A bus error occurred while the message was being sent
0 = A bus error did not occur while the message was being sent
TXREQ: Transmit Request Status bit⁽²⁾
1 = Requests sending a message. Clears the TXABT, TXLARB, and TXERR bits.
0 = Automatically cleared when the message is successfully sent
Note: Clearing this bit in software while the bit is set, will request a message abort.
Unimplemented: Read as ‘0’
TXPRI1:TXPRI0: Transmit Priority bits⁽³⁾
11 = Priority Level 3 (highest priority)
10 = Priority Level 2
01 = Priority Level 1
00 = Priority Level 0 (lowest priority)
Note 1: This bit is automatically cleared when TXREQ is set.
2: While TXREQ is set, Transmit Buffer registers remain read-only.
3: These bits define the order in which transmit buffers will be transferred. They do not
alter the CAN message identifier.
Legend:
C = Clearable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
R = Readable bit W = Writable bit
‘0’ = Bit is cleared
- n = Value at POR
x = Bit is unknown
 2004 Microchip Technology Inc.
DS30491C-page 285