HD64F38602R Datasheet, PDF (125/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 5 Power-Down Modes
5.3.4 Direct Transition from Active (Medium-Speed) Mode to Subactive Mode
When a SLEEP instruction is executed in active (medium-speed) mode while the SSBY, LSON,
and TMA3 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 (4).
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)……(4)
Example:
When φosc/8 and φw/8 are selected as the CPU operating clock before and after
the transition, respectively
Direct transition time = (2 + 1) × 8tosc + 14 × 8tw = 24tosc + 112tw
For the legend of symbols used above, refer to section 21, Electrical Characteristics.
5.3.5 Direct Transition from Subactive Mode to Active (High-Speed) Mode
When a SLEEP instruction is executed in subactive mode while the SSBY and TMA3 bits in
SYSCR1 are set to 1, the LSON bit in SYSCR1 is 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 directly to active (high-
speed) mode via watch mode after the waiting time set in bits STS2 to STS0 in SYSCR1 has
elapsed.
The time from the start of SLEEP instruction execution to the end of interrupt exception handling
(the direct transition time) is calculated by equation (5).
Direct transition time = {(Number of SLEEP instruction execution states) + (Number of internal
processing states)} × (tsubcyc before transition) + (Wait time set in bits
STS2 to STS0) + (Number of interrupt exception handling execution
states) × (tcyc after transition)………………………………………..(5)
Example:
When φw/8 is selected as the CPU operating clock after the transition and wait
time = 8192 states
Direct transition time = (2 + 1) × 8tw + (8192 + 14) × 1tosc = 24tw + 8206tosc
For the legend of symbols used above, refer to section 21, Electrical Characteristics.
Rev. 3.00 May 15, 2007 Page 93 of 516
REJ09B0152-0300