Data Sheet
Table Of Contents
- 1.0 Device Overview
- 2.0 Can Message Frames
- 3.0 Message Transmission
- 4.0 Message Reception
- 5.0 Bit Timing
- 6.0 Error Detection
- 7.0 Interrupts
- 8.0 Oscillator
- 9.0 RESET
- 10.0 Modes of Operation
- 11.0 Register Map
- 12.0 SPI™ Interface
- 12.1 Overview
- 12.2 Reset Instruction
- 12.3 Read Instruction
- 12.4 Read RX Buffer Instruction
- 12.5 Write Instruction
- 12.6 Load TX Buffer Instruction
- 12.7 Request-To-Send (RTS) Instruction
- 12.8 Read Status Instruction
- 12.9 RX Status Instruction
- 12.10 Bit Modify Instruction
- Figure 12-1: Bit Modify
- Table 12-1: SPI™ Instruction Set
- Figure 12-2: Read instruction
- Figure 12-3: Read RX Buffer Instruction
- Figure 12-4: Byte Write instruction
- Figure 12-5: Load TX Buffer
- Figure 12-6: Request-to-send (RTS) instruction
- Figure 12-7: BIT Modify instruction
- Figure 12-8: Read Status instruction
- Figure 12-9: RX StatUs Instruction
- Figure 12-10: SPI™ Input Timing
- Figure 12-11: SPI™ Output TIming
- 13.0 Electrical Characteristics
- 14.0 PackAging Information

© 2005 Microchip Technology Inc. Preliminary DS21801D-page 47
MCP2515
REGISTER 6-3: EFLG – ERROR FLAG
(ADDRESS: 2Dh)
R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0
RX1OVR RX0OVR TXBO TXEP RXEP TXWAR RXWAR EWARN
bit 7 bit 0
bit 7 RX1OVR: Receive Buffer 1 Overflow Flag bit
- Set when a valid message is received for RXB1 and CANINTF.RX1IF = 1
- Must be reset by MCU
bit 6 RX0OVR: Receive Buffer 0 Overflow Flag bit
- Set when a valid message is received for RXB0 and CANINTF.RX0IF = 1
- Must be reset by MCU
bit 5 TXBO: Bus-Off Error Flag bit
- Bit set when TEC reaches 255
- Reset after a successful bus recovery sequence
bit 4 TXEP: Transmit Error-Passive Flag bit
- Set when TEC is equal to or greater than 128
- Reset when TEC is less than 128
bit 3 RXEP: Receive Error-Passive Flag bit
- Set when REC is equal to or greater than 128
- Reset when REC is less than 128
bit 2 TXWAR: Transmit Error Warning Flag bit
- Set when TEC is equal to or greater than 96
- Reset when TEC is less than 96
bit 1 RXWAR: Receive Error Warning Flag bit
- Set when REC is equal to or greater than 96
- Reset when REC is less than 96
bit 0 EWARN: Error Warning Flag bit
- Set when TEC or REC is equal to or greater than 96 (TXWAR or RXWAR = 1)
- Reset when both REC and TEC are less than 96
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