Datasheet

Table Of Contents
© 2009 Microchip Technology Inc. DS39637D-page 291
PIC18F2480/2580/4480/4580
REGISTER 24-11: TXBnDLC: TRANSMIT BUFFER n DATA LENGTH CODE REGISTERS [0 n 2]
U-0 R/W-x U-0 U-0 R/W-x R/W-x R/W-x R/W-x
—TXRTR DLC3 DLC2 DLC1 DLC0
bit 7 bit 0
Legend:
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 7 Unimplemented: Read as ‘0
bit 6 TXRTR: Transmit Remote Frame Transmission Request bit
1 = Transmitted message will have TXRTR bit set
0 = Transmitted message will have TXRTR bit cleared
bit 5-4 Unimplemented: Read as ‘0
bit 3-0 DLC<3:0>: Data Length Code bits
1111 = Reserved
1110 = Reserved
1101 = Reserved
1100 = Reserved
1011 = Reserved
1010 = Reserved
1001 = Reserved
1000 = Data length = 8 bytes
0111 = Data length = 7 bytes
0110 = Data length = 6 bytes
0101 = Data length = 5 bytes
0100 = Data length = 4 bytes
0011 = Data length = 3 bytes
0010 = Data length = 2 bytes
0001 = Data length = 1 bytes
0000 = Data length = 0 bytes
REGISTER 24-12: TXERRCNT: TRANSMIT ERROR COUNT REGISTER
R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0
TEC7 TEC6 TEC5 TEC4 TEC3 TEC2 TEC1 TEC0
bit 7 bit 0
Legend:
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 7-0 TEC<7:0>: Transmit Error Counter bits
This register contains a value which is derived from the rate at which errors occur. When the error
count overflows, the bus-off state occurs. When the bus has 128 occurrences of 11 consecutive
recessive bits, the counter value is cleared.