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ManualsBrandsRENESAS ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller QFP 64 (14x14) 16-Bit 20 MHz I/O number 45
371372373374375376377378379380
Section 15 Controller Area Network for Tiny (TinyCAN)
Rev. 4.00 Mar. 15, 2006 Page 342 of 556
REJ09B0026-0400
15.5.6 TinyCAN Standby Transition
To make this LSI enter or clear standby mode when the TinyCAN is used or to make the
TinyCAN enter or clear module standby mode, follow the procedure below.
Transition from Normal Operation to Standby Mode or Module Standby Mode: This LSI can
make a transition from normal mode to standby mode with the following procedure.
1. Set the halt mode request bit (HLTRQ bit in MCR) to 1.
2. Wait until the reset/halt interrupt flag (RHI bit in TCIRR0) is set to 1.
3. Clear all interrupt request flags (in TCIRR1 and TCIRR0) to 0.
4. Make this LSI enter standby mode or module standby mode. In module standby mode, set the
MSTTC bit in TCMR to 1. Then the TinyCAN enters module standby mode.
Making the CAN bus enter the bus idle state using this procedure will reduce power consumption
of this LSI. The TinyCAN registers retain their settings in standby mode.
Transition from Standby Mode to Normal Operation: This LSI can make a transition from
standby mode to normal mode with the following procedure.
1. When data on the CAN bus changes from recessive to dominant, a falling edge is detected at
the HRXD pin.
2. This causes the WUPI bit in TCIRR1 to be set to 1, and generates an interrupt request.
3. After an interrupt request is issued, the TinyCAN registers resume operation with the settings
before entering standby mode. Change the settings at this timing if necessary.
4. To re-enable communication with the CAN bus, clear both the WUPI bit in TCIRR1 and the
HLTRQ bit in MCR to 0. After 11 recessive bits are consecutively received, communication
will resume.
Note however that the first frame to be received cannot be received normally.
Transition from Module Standby Mode to Normal Operation: The TinyCAN can make a
transition from module standby mode to normal mode with the following procedure.
1. When the MSTTC bit in TCMR is cleared to 0, the TinyCAN registers resume operation with
the settings before entering module standby mode. Change the settings at this timing if
necessary.
2. To re-enable communication with the CAN bus, clear both the HLTRQ bit in MCR to 0. After
11 recessive bits are consecutively received, communication will resume.