Can Register Definitions; Mode Register; Table 22-2. Mod Register; Table 22-3. Mod Register Definitions - Sharp Blue Treak LH75400 User Manual

Controller Area Network

22.3.2 CAN Register Definitions

22.3.2.1 Mode Register

MOD is the Mode Register. The active bits used in this register are Read/Write.
The MOD Register allows the selection of:
• Acceptance Filter Mode
• Self Test Mode
• Listen Only Mode
• Reset Mode.
Bits [3:1] can be written in both Operating Mode and Reset Mode.
BIT
FIELD
RESET
RW
BIT
FIELD
RESET
RW
ADDR
BIT NAME
31:5
4
3 AFM
2 STM
1 LOM
0 RM
22-8
31 30 29 28 27
0 0 0 0
R R R R
15 14 13 12 11
0 0 0 0
R R R R

Table 22-3. MOD Register Definitions

Reserved Writing to these bits has no effect. Reading returns 0.
///
/// Reserved Do not modify. Read as 0.
Acceptance Filter Mode
0 = Dual filter. Receive data is filtered using two shorter filters.
1 = Single filter. Receive data is filtered using one 4-byte filter.
Self Test Mode
0 = Normal operation. An acknowledge is required for successful transmission.
1 = Enable Self Test Mode. In this mode, a full node test is possible without any other active
node on the bus using the Self-Reception request command.
Listen Only Mode
0 = Normal operation. The error counters cannot be changed unless in Reset Mode.
1 = Enable Listen Only Mode. In this mode, the CAN Controller does not send an acknowledge
to the CAN bus, even when a message is received successfully.
Reset Mode
0 = Normal Operation. The CAN Controller returns to Operating Mode on the 1-to-0 transition
of this bit.
1 = Reset Mode. Any message currently being transmitted or received is aborted and Reset
Mode is entered.
LH75400/01/10/11 (Preliminary) User's Guide

Table 22-2. MOD Register

26 25 24 23
///
0 0 0 0 0
R R R R R
10 9 8 7
///
0 0 0 0 0
R R R R R
0xFFFC5000 + 0x00
DESCRIPTION
6/17/03
22 21 20 19 18
0 0 0 0 0
R R R R R
6 5 4 3 2
/// AFM STM LOM
0 0 0 0 0
R R RW RW RW
17 16
0 0
R R
1 0
RM
0 1
RW RW