SH7203 Datasheet, PDF (1456/1686 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 28 Power-Down Modes
When deep standby mode is canceled by interrupts (NMI or IRQ) or a manual reset, the deep
standby cancel source flag register (DSFR) can be used to confirm which interrupt has canceled
the mode.
Pins retain the state immediately before the transition to deep standby mode. However, in system
activation through the external bus, the retention of the states of the external bus control pins is
cancelled so that programs can be fetched after cancellation of deep standby mode. Other pins,
after cancellation of deep standby mode, continue to retain the pin states until writing 0 to the
IOKEEP bit in DSFR after reading 1 from the same bit. In system activation from the on-chip
RAM (for data retention), after cancellation of deep standby mode, both the external bus control
pins and other pins continues to retain the pin states until writing 0 to the IOKEEP bit in DSFR
after reading 1 from the same bit. Reconfiguration of peripheral functions is required to return to
the previous state of deep standby mode. Peripheral functions include all functions such as CPG,
INTC, BSC, I/O ports, PFC, and peripheral modules. After the reconfiguration, the retention of the
pin state can be canceled and the LSI returns to the state prior to the transition to deep standby
mode by reading 1 from the IOKEEP bit in DSFR and then writing 0 to it.
(4) Notes on Transition to Deep Standby Mode
After deep standby mode is specified, interrupts other than those set as cancel sources in the deep
standby cancel source select register are masked. If multiple interrupts are set as cancel sources in
the deep standby cancel source select register and more than one of these cancel sources are input,
multiple cancel source flags are set.
In addition, if a SLEEP instruction to initiate the transition to deep standby mode coincides with
an NMI or IRQ interrupt, or with a manual reset, acceptance of the interrupt may cause
cancellation of deep standby mode.
Rev. 2.00 Apr. 16, 2008 Page 1426 of 1652
REJ09B0313-0200