upd70f3422gj-gae-qs-ax Renesas Electronics Corporation., upd70f3422gj-gae-qs-ax Datasheet - Page 731

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

CAN Controller (CAN)
19.12.3 Example of using power saving modes
In some application systems, it may be necessary to place the CPU in a power
saving mode to reduce the power consumption. By using the power saving
mode specific to the CAN module and the power saving mode specific to the
CPU in combination, the CPU can be woken up from the power saving status
by the CAN bus.
Here is an example for using the power saving modes.
• First, put the CAN module in the CAN sleep mode (CnCTRL.PSMODE[1:0]
• The CAN module is automatically released from CAN sleep mode
• The CPU, in response to INTWUP, can release its own power saving mode
• If an edge transition from recessive to dominant is detected at the CAN
• The other functions, however, do not operate, because clock supply to the
• The CPU, in response to INTWUP
• When clock supply is resumed, the CAN module is immediately released
Preliminary User’s Manual U17566EE1V2UM00
= 01B). Next, put the CPU in the power saving mode. If an edge transition
from recessive to dominant is detected at the CAN reception pin (CRXDn) in
this status, the CnINTS.CINTS5 is set to 1 and a wakeup interrupt
(INTWUP) is generated, provided CnINTS5 is enabled by CnIE.CIE5 = 1.
(PSMODE = 00B) and returns to normal operation mode.
and return to normal operation mode.
To further reduce the power consumption of the CPU, the internal clocks—
including that of the CAN module—may be stopped. In this case, the
operating clock supplied to the CAN module is stopped after the CAN
module has been put in CAN sleep mode. Then the CPU enters a power
saving mode in which the clock supplied to the CPU is stopped.
reception pin (CRXDn) in this status, the CAN module can set the
CnINTS.CINTS5 = 1 and generate the wakeup interrupt (INTWUP) even if it
is not supplied with the clock.
CAN module is stopped, and the module remains in CAN sleep mode.
– releases its power saving mode,
– resumes supply of the internal clocks—including the clock to the CAN
– starts instruction execution.
from CAN sleep mode and returns to normal operation mode
(CnCTRL.PSMODE[1:0] = 00B).
module—after the oscillation stabilization time has elapsed, and
Chapter 19
731