upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 728

• Manufacturer Part Number: upd70f3422gj-gae-qs-ax
• Description: 32-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

Chapter 19
728
19.12.1 CAN sleep mode
19.12 Power Saving Modes
(1)
The CAN sleep mode can be used to set the CAN Controller to stand-by mode
in order to reduce power consumption. The CAN module can enter the CAN
sleep mode from all operation modes. Release of the CAN sleep mode returns
the CAN module to exactly the same operation mode from which the CAN
sleep mode was entered.
In the CAN sleep mode, the CAN module does not transmit messages, even
when transmission requests are issued or pending.
Entering CAN sleep mode
The CPU issues a CAN sleep mode transition request by writing 01B to the
CnCTRL.PSMODE1 and CnCTRL.PSMODE0 bits.
This transition request is only acknowledged only under the following
conditions.
(i) The CAN module is already in one of the following operation modes
(ii) The CAN bus state is bus idle (the 4th bit in the interframe space is recessive)
(iii) No transmission request is pending
Preliminary User’s Manual U17566EE1V2UM00
•Normal operation mode
•Normal operation mode with ABT
•Receive-only mode
•Single-shot mode
•Self-test mode
•CAN stop mode in all the above operation modes
Note: If the CAN bus is fixed to dominant, the request for transition to the
CAN sleep mode is held pending.
If any one of the conditions mentioned above is not met, the CAN module
will operate as follows.
•If the CAN sleep mode is requested from the initialization mode, the CAN
•If the CAN bus state is not bus idle (i.e., the CAN bus state is either
•If a request for transition to the initialization mode and a request for
sleep mode transition request is ignored and the CAN module remains
in the initialization mode.
transmitting or receiving) when the CAN sleep mode is requested in one
of the operation modes, immediate transition to the CAN sleep mode is
not possible. In this case, the CAN sleep mode transition request has to
be held pending until the CAN bus state becomes bus idle (the 4th bit in
the interframe space is recessive). In the time from the CAN sleep mode
request to successful transition, the PSMODE1 and PSMODE0 bits
remain 00B. When the module has entered the CAN sleep mode, the
PSMODE1 and PSMODE0 bits are set to 01B.
transition to the CAN sleep mode are made at the same time while the
CAN module is in one of the operation modes, the request for the
initialization mode is enabled. The CAN module enters the initialization
mode at a predetermined timing. At this time, the CAN sleep mode
request is not held pending and is ignored.
CAN Controller (CAN)