Section 27 Power-Down Modes
Rev. 3.00 Jan 25, 2006 page 788 of 872
REJ09B0286-0300
resumes at the end of the bus cycle. In module stop mode, the internal states of modules other than
the MCIF, SCI, D/A converter, A/D converter, PWM, and PWMX are retained.
After the reset state is cancelled, all modules other than DTC are in module stop mode.
While an on-chip peripheral module is in module stop mode, read/write access to its registers is
disabled.
27.11 Direct Transitions
The CPU executes programs in three modes: high-speed, medium-speed, and subactive. When a
direct transition is made from high-speed mode to subactive mode, there is no interruption of
program execution. A direct transition is enabled by setting the DTON bit in LPWRCR to 1 and
then executing the SLEEP instruction. After a transition, direct transition exception handling
starts.
The CPU makes a transition to subactive mode when the SLEEP instruction is executed in high-
speed mode with the SSBY bit in SBYCR set to 1, the LSON bit and DTON bit in LPWRCR set
to 11, and the PSS bit in TSCR (WDT_1) set to 1.
To make a direct transition to high-speed mode after the time set in the STS2 to STS0 bits in
SBYCR has elapsed, execute the SLEEP instruction in subactive mode with the SSBY bit in
SBYCR set to 1, the LSON bit and DTON bit in LPWRCR set to 01, and the PSS bit in TSCR
(WDT_1) set to 1.
In high-speed mode or medium-speed mode, the system clock source (
φ
or
φ
24) can be switched
by using one of the following two methods according to the CKCHGE bit in SYSCR2. When the
CKCHGE bit is cleared to 0, after a transition to software standby mode or watch mode is made,
the system clock source is switched by a wakeup via an interrupt. When the CKCHGE bit is set to
1, a transition similar to active-subactive direct transition is made, and direct transition exception
handling is executed after a direct transition.
In high-speed mode or medium-speed mode, do not execute a SLEEP instruction when a setting
for making a direct transition to subactive mode and a setting for switching the system clock
source at a direct transition are made. When the system clock source is to be switched at a direct
transition, make sure the SLEEP instruction does not conflict with other interrupt sources.
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...