878
24.11
Direct Transitions
24.11.1
Overview of Direct Transitions
There are three modes, high-speed, medium-speed, and sub-active, in which the CPU executes
programs. When a direct transition is made, there is no interruption of program execution when
shifting between high-speed and sub-active modes. Direct transitions are enabled by setting the
LPWRCR DTON bit to 1, then executing the SLEEP instruction. After a transition, direct
transition interrupt exception processing starts.
(1) Direct Transitions from High-Speed Mode to Sub-Active Mode
Execute the SLEEP instruction in high-speed mode when the SBYCR SSBY bit = 1, LPWRCR
LSON bit = 1, and DTON bit = 1, and TSCR (WDT1) PSS bit = 1 to make a transition to sub-
active mode.
(2) Direct Transitions from Sub-Active Mode to High-Speed Mode
Execute the SLEEP instruction in sub-active mode when the SBYCR SSBY bit = 1, LPWRCR
LSON bit = 0, and DTON bit = 1, and TSCR (WDT1) PSS bit = 1 to make a direct transition to
high-speed mode after the time set in SBYCR STS2 to STS0 has elapsed.
24.12
ø Clock Output Disabling Function
Output of the ø clock can be controlled by means of the PSTOP bit in SCKCR, and DDR for the
corresponding port. When the PSTOP bit is set to 1, the ø clock stops at the end of the bus cycle,
and ø output goes high. ø clock output is enabled when the PSTOP bit is cleared to 0. When DDR
for the corresponding port is cleared to 0, ø clock output is disabled and input port mode is set.
Table 24-6 shows the state of the ø pin in each processing state.
Table 24-6 ø Pin State in Each Processing State
DDR
0
1
1
PSTOP
—
0
1
Hardware standby mode
High impedance
High impedance
High impedance
Software standby mode, watch
mode, and direct transition
High impedance
Fixed high
Fixed high
Sleep mode and subsleep mode
High impedance
ø output
Fixed high
High-speed mode, medium-speed
mode, and subactive mode
High impedance
ø output
Fixed high
Содержание H8S/2631
Страница 28: ...xviii Appendix G Package Dimensions 1154 ...
Страница 341: ...316 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 9 8 Memory Mapping in Block Transfer Mode ...
Страница 918: ...905 ø DREQ0 DREQ1 tDRQS tDRQH Figure 25 19 DMAC DREQ Input Timing ...
Страница 955: ...943 A 2 Instruction Codes Table A 2 shows the instruction codes ...