3069RF-ZTAT Datasheet, PDF (199/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

When software standby mode is used, the BRLE bit should be cleared to 0 in BRCR before
executing the SLEEP instruction.
Similar contention in a transition to self-refresh mode may prevent dependable strobe
waveform output. This can also be avoided by clearing the BRLE bit to 0 in BRCR.
• Immediately after self-refreshing is cleared, external bus release is possible during a given
period until the start of a CPU cycle. Attention must be paid to the RAS state to ensure that
the specification for the RAS precharge time immediately after self-refreshing is met.
External bus released
φ
Refresh cycle
CPU cycle
Refresh cycle
RFSH
Refresh
request
BACK
Figure 6.35 Bus-Released State and Refresh Cycles
φ
BREQ
BACK
Address bus
Software standby mode
Strobe
Figure 6.36 Bus-Released State and Software Standby Mode
Rev. 5.0, 09/04, page 177 of 978