CAN FD v2.0
41
PG223 December 5, 2018
Chapter 2:
Product Specification
RX FIFO Watermark Register (Address 00EC)
5:0
RI
R
0
RX FIFO-0 Read Index (0 to 63).
Each time IRI bit is set, core increments read index by + 1
(provided FILL level is not 0) and maintains it for Host to access
next available message.
• RI = 0x0 -> Next message read starts from location =
0x2100.
• RI = 0x1 -> Next message read starts from location =
0x2148.
RI is maintained if CEN bit is cleared.
RI gets reset to 0 if soft or hard reset is asserted.
Notes:
1. This register space is reserved for RX Mailbox buffer mode. Write has no effect and read returns 0.
Table 2-29:
RX FIFO Watermark Register
Bits
Name
Access Default
Value
Description
31:21
Reserved
–
0
Reserved.
20:16
RXFP
R/W
0x1f
Receive Filter Partition.
Received messages which match Filter-Mask pairs from 0 to RXFP
are stored in RX FIFO-0.
Received messages which match Filter-Mask pairs RXFP+1 and
above are stored into RX FIFO-1.
Note:
This field is available only when RX FIFO-1 is enabled.
This field can be changed when CEN = 0.
13:8
RXFWM_1
R/W
0xf
RX FIFO-1 Full Watermark.
Note:
This field is available only when RX FIFO-1 is enabled.
RX FIFO-1 generates FULL interrupt based on the value
programmed in this field. Set it within a 1-63 range.
The RX FIFO-1 Full Watermark interrupt in the ISR register
continues to assert as long as the RX FIFO-1 Fill Level is above
RX FIFO-1 Full watermark.
This field can be written to only when CEN bit in SRR is 0.
7:6
Reserved
–
0
Reserved.
Table 2-28:
RX FIFO Status Register
(Cont’d)
Bits
Name
Access Default
Value
Description