HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 781

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

20.4.5
1. When the chip enters standby mode during use of the cache, disable the cache before making
2. If an on-chip peripheral register is written in the 10 clock cycles before the chip transits to
3. When using clock mode 0, 1, or 2, the CKIO pin is the clock output pin. Note the following
Before entering the standby mode, stop operation of the internal DMAC (E-DMAC or DMAC).
20.5
20.5.1
By setting one of bits MSTP11–MSTP3, MSTP1 to 1 in standby control register 1 or 2, the supply
of the clock to the corresponding on-chip peripheral module or DSP unit can be halted. This
function can be used to reduce the power consumption. Do not perform read/write operations for a
module in module standby mode.
With the module standby function, the external pins of the DMAC and SIO0–SIO2 on-chip
peripheral modules retain their states prior to halting, as do DMAC, DSP, and SIO0–SIO2
registers. The external pins of the FRT, SCIF1–2, and TPU are reset and all their registers are
initialized.
An on-chip peripheral module corresponding to a module standby bit must not be switched to the
module standby state while it is running. Also, interrupts from a module placed in the module stop
state should be disabled.
20.5.2
Clear the module standby function by clearing the MSTP11–MSTP3, MSTP1 bits, or by a power-
on reset or manual reset.
the mode transition. Initialize the cache beforehand when the cache is used after returning to
standby mode. The contents of the on-chip RAM are not retained in standby mode when cache
is used as on-chip RAM.
standby mode, read the register before executing the SLEEP instruction.
when standby mode is used in these clock modes. When standby mode is canceled by NMI, an
unstable clock is output from the CKIO pin during the oscillation settling time after NMI input.
This also applies to clock output in the case of cancellation by a power-on reset or manual
reset. Power-on reset and manual reset input should be continued for a period at least equal to
for the oscillation settling time.
Notes on Standby Mode
Module Standby Function
Transition to Module Standby Function
Clearing the Module Standby Function
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