M306H7MG-XXXFP Datasheet, PDF (323/329 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with DATA ACQUISITION CONTROLLER

M306H7MG-XXXFP/MC-XXXFP/FGFP
19. USAGE NOTES
19.12 Other Notes
19.12.1 When the power is being turned on or off
Start VCC1, VCC2, VDD2 and AVCC simultaneously.
While this device is operating, set these pins to the same electric potential.
Also, turn off VCC1, VCC2, VDD2 and AVCC simultaneously when the power supply is being turned off.
When using VCC1 < VCC2, ensure voltage of VCC1 will not exceed voltage of VCC2 while the power is being
turned on or off.
Execute in the following procedure when VCC1 is turned off (VCC2 voltage is supplied).
19.12.2 Procedure of VCC1 OFF(Note 1)
(1) Disable an interrupt which uses pins related to VCC1.
(2) Stop peripheral functions related to VCC1 (Note 2).
(3) Set pins related to VCC1 to input mode.
(4) VCCOFF pin is switched from “L” to “H” .
(5) Turn off VCC1.
19.12.3 Procedure of VCC1 ON
(1) Turn on VCC1.
(2) VCCOFF pin (91-pin) is switched from “H” to “L” .
(3) Set pins VCC1, Peripheral function and Interrupt.
Note 1: Refer to the following “Additions” for details of procedures (1) to (4).
Note 2: Only when the input from pins related to VCC1 is used. Refer to the following “Additions” for details.
<Additions>
(1) Disable an affected interrupt by pins related to VCC1.
Disable an affected interrupt by pins related to VCC1 by setting the interrupt priority level selection and the
interrupt request bits in the the following interrupt control register to “0”.
In the transitional state when changing the power supply voltage including being turned on or off, ensure
each voltage of VCC1, VDD2, and VDD3 will not exceed voltage of VCC2.
TA0IC to TA4IC (timer A interrupt control register)
INT0 to INT2IC (external interrupt control register)
S0RIC to S2RIC (UART receive interrupt control register)
Even if other interrupts are disabled without any problem in software, clear the I flag and it is also possible to
execute the above interrupt disable process after the procedure (4).
(2) Stop peripheral functions related to VCC1
Stop the function when pins related to VCC1 input affect.
When pins related to VCC1 input affect as follows:
•When operating in timer A (TA0 to TA4) and the event count mode
•When the gate input function is used in the event count mode, the one-shot timer, and PWM mode.
(When the MR2 bit in the timer A mode registers TA0MR to TA4MR are set to “1”)
•When UART to UART2 reception are set
Set the following in these cases.
•Timer A
Set the timer count start flags of timers A0 to A4 (TA0S to TA4S bits in the TABSR register) to “0”.
•UART reception
Set the RE and TE bits in the U0C1 to U2C1 registers to “0”.
Rev.2.10 Oct 25, 2006 Page 323 of 326
REJ03B0152-0210