Receive Buffer Start Address Register; Table 22-36. Rbsa Register; Table 22-37. Rbsa Register Definitions - Sharp Blue Treak LH75400 User Manual

LH75400/01/10/11 (Preliminary) User's Guide

22.3.2.20 Receive Buffer Start Address Register

RBSA is the Receive Buffer Start Address Register. The active bits used in this register
are Read/Write.
This register records the current location of the RX FIFO Read Pointer within the 64-byte
RX FIFO as a value between 0 and 63.
• Location 0 corresponds to CAN Offset 0x80.
• Location 63 corresponds to CAN Offset 0x17C.
This register is reset to 00h by a System Reset, but is left unchanged by a Software Reset
(which also does not change the FIFO contents). However, the RX FIFO Write Pointer is
set by a Software Reset to the value of the RX FIFO Read Pointer. As a result, the data
accessed by the Receive Buffer following a Software Reset is overwritten by the next mes-
sage to be recorded in the RX FIFO.
NOTE: It is only possible to write to this register in Reset Mode.
BIT
FIELD
RESET
RW
BIT
FIELD
RESET
RW
ADDR
BIT
31:8
7:0

Table 22-36. RBSA Register

31 30 29 28 27
0 0 0 0 0
R R R R R
15 14 13 12 11
0 0 0 0 0
R R R R R

Table 22-37. RBSA Register Definitions

NAME
Reserved Writing to these bits has no effect. Reading returns 0.
///
RX FIFO Read Pointer Location Specifies the current location of
RMC.4 - RMC.0
the RX FIFO Read Pointer within the 64-byte RX FIFO.
26 25 24 23
///
0 0 0 0
R R R R
10 9 8 7
///
0 0 0 0
R R R R
0xFFFC5000 + 0x78
DESCRIPTION
6/17/03
Controller Area Network
22 21 20 19 18
0 0 0 0 0
R R R R R
6 5 4 3 2
RBSA
0 0 0 0 0
R RW RW RW RW
17 16
0 0
R R
1 0
0 0
RW RW
22-29