Renesas M16C/60 Series Hardware Manual page 231

Under development
This document is under development and its contents are subject to change.
M16C/6N5 Group
CAN Operation Mode
The CAN operation mode is activated by clearing the Reset bit of the C0CTLR register. Entering the
operation mode initiates the following functions by the module:
• The module's communication functions are released and it becomes an active node on the network
and may transmit and receive CAN messages.
• Release the internal fault confinement logic including receive and transmit error counters. The module
may leave the CAN operation mode depending on the error counts.
Within the CAN operation mode the module may be in three different sub modes, depending on which
type of communication functions are performed:
• Module idle: The modules receive and transmit sections are inactive.
• Module receives: The module receives a CAN message sent by another node.
• Module transmits: The module transmits a CAN message. The module may receive its own message
simultaneously when the loopback function is enabled.
Figure 1.19.19 shows sub modes of the CAN operation mode.
Figure 1.19.19 Sub Modes of CAN Operation Mode
CAN Sleep Mode
The CAN sleep mode is activated by setting the Sleep bit of the C0CTLR register. It should never be
activated from the CAN operation mode but only via the CAN reset/initialization mode. Entering the CAN
sleep mode instantly stops the modules clock supply and thereby reduces power dissipation.
Bus off State
The bus off state is entered according to the fault confinement rules of the CAN specification. It can be
quit instantly to error active state by setting the RetBusOff bit of the CiCTLR register to "1" (force return from
buss off) and CAN communication becomes possible again. This does not alter any CAN registers, except
CiRECR and CiTECR registers.
Rev.1.00 2003.05.30 page 217
Module idle
TrmState = 0
Start
RecState = 0
transmission
Finish
transmission
Module transmits
TrmState = 1
RecState = 0
Lost in arbitration
Detect
an SOF
Finish
reception
Module receives
TrmState = 0
RecState = 1
CAN Module