APPENDIX A RESTRICTIONS ON V
R
4181
User’s Manual U14272EJ3V0UM
438
(2) With SDRAM
When the RSTSW# signal goes low, the CLKEN (CKE) signal goes high. While the CLKEN signal is high, the
self-refresh mode of SDRAM may be released. However, because the SDCLK signal is kept low, this problem
does not occur in SDRAM that requires the rising edge of the SDCLK signal to release the self-refresh mode.
Figure A-3. Release of Self-Refresh Mode by RSTSW# Signal (SDRAM)
CLKEN (output)
SDCLK (output)
L
RSTSW# (input)
RTC (internal)
SDCS(1:0)# (output)
SDRAS# (output)
CAS# (output)
[Workaround]
Mask the RSTSW# signal via an external circuit using the MPOWER signal and GPIO pin, so that the
RSTSW# signal does not go low in the Hibernate mode.
Содержание VR4181 mPD30181
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