User`s manual

12
3. Low-Power States (Sleep, Software Standby, and Module Standby)
For low-power consumption, the SH7729R and SH7709S have sleep, software standby, and
module standby states.
The sleep, software standby, and module standby states are switched using the SLEEP
instruction. When the emulator is used, only the sleep state can be cleared with either the
normal clearing function or with the [STOP] button, and a break will occur. Note that if a
command has been entered in standby mode or module standby mode, no commands can be
used from the emulator. The states cannot be canceled by the [STOP] button.
Notes: 1. The memory must not be accessed or modified in sleep mode.
2. When the [STOP] button is clicked in sleep mode, a break does not occur immediately
after executing the SLEEP instruction. The number of instructions to be proceeded
differs according to the emulator environment or operating frequency of the chip. It is
about 500 instructions when the Pentium III 800-MHz PC is used and the operating
frequency is 25 MHz.
3. When the UBC is set to be used, do not set the UBC to the standby mode.
4. When the SLEEP instruction is executed by STEP-type commands to switch the mode
to sleep, the emulator does not enter sleep mode, and execution skips to the next
instruction. Do not execute the SLEEP instruction to switch the mode to standby
because a TIMEOUT error will occur.
4. Reset Signals (/RESETP and /RESETM)
The SH7729R and SH7709S reset signals (/RESETP and /RESETM) are only valid during
emulation started with clicking the GO or STEP-type button. If these signals are enabled on
the user system in command input wait state, they are not sent to the SH7729R or SH7709S.
Note: Do not break the user program when the /RESETP, /RESETM, /BREQ, and /WAIT
signals are being low. A TIMEOUT error will occur. If the /BREQ or /WAIT signal is
fixed to low during break, a TIMEOUT error will occur at memory access.
5. Direct Memory Access Controller (DMAC)
The DMAC operates even when the emulator is used. When a data transfer request is
generated, the DMAC executes DMA transfer.
6. Memory Access during User Program Execution
When a memory is accessed from the memory window, etc. during user program execution,
the user program is resumed after it has stopped in the E10A emulator to access the memory.
Therefore, realtime emulation cannot be performed.
The stopping time of the user program is as follows:
Environment:
Host computer: 800 MHz (Pentium
®
III)
Operating system: Windows
®
2000
SH7729R: 50 MHz (CPU clock)
JTAG clock: 15 MHz