HD64F38602R Datasheet, PDF (124/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 5 Power-Down Modes
5.3.2 Direct Transition from Active (High-Speed) Mode to Subactive Mode
When a SLEEP instruction is executed in active (high-speed) mode while the SSBY, TMA3, and
LSON bits in SYSCR1 are set to 1 and the DTON bit in SYSCR2 is set to 1, a transition is made
to subactive mode via watch mode.
The time from the start of SLEEP instruction execution to the end of interrupt exception handling
(the direct transition time) is calculated by equation (2).
Direct transition time = {(Number of SLEEP instruction execution states) + (Number of internal
processing states)} × (tcyc before transition) + (Number of interrupt
exception handling execution states) × (tsubcyc after transition)…..…(2)
Example: When φw/8 is selected as the subactive operating clock after the transition
Direct transition time = (2 + 1) × 1tosc + 14 × 8tw = 3tosc + 112tw
For the legend of symbols used above, refer to section 21, Electrical Characteristics.
5.3.3 Direct Transition from Active (Medium-Speed) Mode to Active (High-Speed) Mode
When a SLEEP instruction is executed in active (medium-speed) mode while the SSBY and
LSON bits in SYSCR1 are cleared to 0, the MSON bit in SYSCR2 is cleared to 0, and the DTON
bit in SYSCR2 is set to 1, a transition is made to active (high-speed) mode via sleep mode.
The time from the start of SLEEP instruction execution to the end of interrupt exception handling
(the direct transition time) is calculated by equation (3).
Direct transition time = {(Number of SLEEP instruction execution states) + (Number of internal
processing states)} × (tcyc before transition) + (Number of interrupt
exception handling execution states) × (tcyc after transition)………..(3)
Example: When φosc/8 is selected as the CPU operating clock before the transition
Direct transition time = (2 + 1) × 8tosc + 14 × 1tosc = 38tosc
For the legend of symbols used above, refer to section 21, Electrical Characteristics.
Rev. 3.00 May 15, 2007 Page 92 of 516
REJ09B0152-0300