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3. Low-Power States (Sleep, Software Standby, Module Standby, and U Standby)
For low-power consumption, the SH7339 has sleep, software standby, module standby, and U
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. For the U standby
state, refer to section 2.2.8, Notes on U Standby State.
Note: The memory must not be accessed or modified in sleep state.
4. Reset Signals
The SH7339 reset signals 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 SH7339.
Note: Do not break the user program when the /RESETP, /BREQ, or /WAIT signal is 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-USB 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)
SH7339: 60 MHz (CPU clock)
JTAG clock: 10 MHz (TCK clock)
When a one-byte memory is read from the command-line window, the stopping time will be
about 45 ms.
7. Memory Access during User Program Break
The emulator can download the program for the flash memory area (for details, refer to section
6.22, Download Function to the Flash Memory Area, in the Debugger Part of the SuperH
TM
Family E10A-USB Emulator User’s Manual). Other memory write operations are enabled for
the RAM area. Therefore, an operation such as memory write or BREAKPOINT should be set
only for the RAM area.