DS791 Datasheet, PDF (27/46 Pages) Xilinx, Inc – LogiCORE IP AXI Controller

LogiCORE IP AXI Controller Area Network (axi_can) (v1.03.a)
Table 31: Identifier Word Bit Descriptions
Bit(s)
Name
Core Access
0–10
ID[28..18]
11
SRR/RTR
12
IDE
13–30
ID[17..0]
Reads from RX
FIFO
Writes to
TX FIFO and
TX HPB
Reads from RX
FIFO
Writes to
TX FIFO and
TX HPB
Reads from RX
FIFO
Writes to
TX FIFO and
TX HPB
Reads from RX
FIFO
Writes to
TX FIFO and
TX HPB
Reads from RX
FIFO
31
RTR
Writes to
TX FIFO and
TX HPB
Default
Value
Description
Standard Message ID: The Identifier portion for a Standard
Frame is 11 bits.
0
These bits indicate the Standard Frame ID.
This field is valid for both Standard and Extended Frames.
Substitute Remote Transmission Request: This bit
differentiates between data frames and remote frames.
Valid only for Standard Frames. For Extended frames this bit
0
is 1.
‘1’ = Indicates that the message frame is a Remote Frame.
‘0’ = Indicates that the message frame is a Data Frame.
Identifier Extension: This bit differentiates between frames
using the Standard Identifier and those using the Extended
0
Identifier. Valid for both Standard and Extended Frames.
‘1’ = Indicates the use of an Extended Message Identifier.
‘0’= Indicates the use of a Standard Message Identifier.
Extended Message ID: This field indicates the Extended
Identifier.
0
Valid only for Extended Frames.
For Standard Frames, reads from this field return ‘0’s
For Standard Frames, writes to this field should be ‘0’s
Remote Transmission Request: This bit differentiates
between data frames and remote frames.
Valid only for Extended Frames.
0
‘1’ = Indicates that the message object is a Remote Frame
‘0’ = Indicates that the message object is a Data Frame
For Standard Frames, reads from this bit returns ‘0’
For Standard Frames, writes to this bit should be ‘0’
Table 32: DLC Word Bit Descriptions
Bit(s)
Name
Core Access
0–3
DLC
Read/Write
4–31
Reserved
Read/Write
Default
Value
Description
Data Length Code:
0
This is the data length portion of the control field of the CAN
frame. This indicates the number valid data bytes in Data
Word 1 and Data Word 2 registers.
Reads from this field return ‘0’s.
Writes to this field should be ‘0’s.
DS791 June 22, 2011
www.xilinx.com
27
Product Specification