Datasheet

 2003-2019 Microchip Technology Inc. DS20001801J-page 67
MCP2515
TABLE 12-1: SPI INSTRUCTION SET
Instruction Name Instruction Format Description
RESET 1100 0000 Resets internal registers to the default state, sets Configuration
mode.
READ 0000 0011 Reads data from the register beginning at selected address.
READ RX BUFFER 1001 0nm0 When reading a receive buffer, reduces the overhead of a normal
READ command by placing the Address Pointer at one of four
locations, as indicated by ‘n,m’.
Note: The associated RX flag bit, RXnIF (CANINTF), will be
cleared after bringing
CS high.
WRITE 0000 0010 Writes data to the register beginning at the selected address.
LOAD TX BUFFER 0100 0abc When loading a transmit buffer, reduces the overhead of a normal
WRITE command by placing the Address Pointer at one of six
locations, as indicated by ‘a,b,c’.
RTS
(Message
Request-to-Send)
1000 0nnn Instructs controller to begin message transmission sequence for
any of the transmit buffers.
READ STATUS 1010 0000 Quick polling command that reads several status bits for transmit
and receive functions.
RX STATUS 1011 0000 Quick polling command that indicates filter match and message
type (standard, extended and/or remote) of received message.
BIT MODIFY 0000 0101 Allows the user to set or clear individual bits in a particular
register.
Note: Not all registers can be bit modified with this command.
Executing this command on registers that are not bit
modifiable will force the mask to FFh. See the register
map in Section 11.0 “Register Map” for a list of the
registers that apply.
1000 0nnn
Request-to-Send for TXBO
Request-to-Send for TXB1
Request-to-Send for TXB2