H8S2607 Datasheet, PDF (633/710 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 21 Power-Down Modes
21.10 Direct Transitions
21.10.1 Overview of Direct Transitions
There are three modes, high-speed, medium-speed, and subactive, in which the CPU executes
programs. When a direct transition is made, there is no interruption of program execution in
shifting between high-speed and subactive modes. Direct transitions are enabled by setting the
DTON bit in LPWRCR to 1, then executing the SLEEP instruction. After a transition, direct
transition interrupt exception handling starts.
Direct Transition from High-Speed Mode to Subactive Mode: Execute the SLEEP instruction
in high-speed mode with the SSBY bit in SBYCR = 1, the LSON bit in LPWRCR = 1, the DTON
bit = 1, and the PSS bit in TCSR (WDT1) = 1, to make a direct transition to subactive mode.
Direct Transition from Subactive Mode to High-Speed Mode: Execute the SLEEP instruction
in subactive mode with the SSBY bit in SBYCR = 1, the LSON bit in LPWRCR = 0, the DTON
bit = 1, and the PSS bit in TCSR (WDT_1) = 1, to make a direct transition to high-speed mode
after the time set in the STS2 to STS0 bits in SBYCR has elapsed.
Rev. 1.00 Jan. 29, 2008 Page 593 of 666
REJ09B0427-0100