
CHAPTER 19 CAN CONTROLLER
Preliminary User’s Manual U16541EJ1V0UM
666
19.8.3
Transition from INIT mode to operational mode
The CAN module in each CAN I/F channel can be switched to the following operational modes.
“Normal operating mode”
“Normal operating mode with automatic block transmission”
“Receive-only mode”
“Single-shot mode”
“Self-test mode”
Figure 19-32. Transition to CAN Module Operational Modes
CAN I/F
ch annel
disab led
GOM = 1
CAN module INIT mode
OPMODE[2:0] =00H
CAN module
" Nor mal operating
mode "
OPMODE[2:0]=01H
OPMODE[2:0]=00H
and
CAN bus id le
CAN module "normal
operating mode
wi th
automatic block
transmission"
OPMODE[2:0]=02H
OPMODE[2:0]=00H
and
CAN bus id le
CAN module
"
Sin gle -shot mode
"
OPMODE[2:0]=04
H
OPMODE[2:0]=04H
OPMODE[2:0]=00H
and
CAN bus id le
OPMODE[2:0]=00H
and
CAN bus busy
OPMODE[2:0]=00H
and
CAN bus busy
OPMODE[2:0]=00H
and
CAN bus busy
(All C AN module s
in IN IT mode )
and
(GOM = 0)
Not all CAN modules in INIT
mode
and
GOM = 0
EFSD = 1
and
GOM = 0
OPMODE[2:0]=03H
CAN module
" Recei ve-only mode "
OPMODE[2:0]=03H
OPMODE[2:0]=00H
and
CAN bus id le
OPMODE[2:0]=00H
and
CAN bus busy
CAN module
" Self-test mode"
OPMODE[2:0]=05 H
OPMODE[2:0]=05H
OPMODE[2:0]=00H
and
CAN bus id le
OPMODE[2:0]=00H
and
CAN bus busy
OPMODE[2:0]=02H
RESET
Release RESET
The transition from INIT mode to the operational modes is controlled by the bit strings OPMODE2 to OPMODE0 in
the C0CTRL register.
Changing from one operational mode to another requires shifting to INIT mode in between. The CAN module
refuses CPU attempts to change from one operational mode to another directly.
Transition requests from the operational modes to the INIT mode are not directly accepted by the CAN module
when the CAN bus is not idle (i.e. frame reception or transmission is ongoing), but it is kept until the CAN module
detects the first bit of intermission.
As soon the above mentioned condition is detected, the transition from the
operational mode to the INIT mode is executed and the OPMODE2 to OPMODE0 bit string values change to 00H.
The CPU has to confirm the proper transition to INIT mode by reading the OPMODE2 to OPMODE0 bit strings until
OPMODE2 to OPMODE0 = 000B.