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Section 12 Bus State Controller (BSC)
Rev. 4.00 Sep. 14, 2005 Page 367 of 982
REJ09B0023-0400
Self-refresh timing is shown in figure 12.30. Settings must be made so that self-refresh
clearing and data retention are performed correctly, and auto-refreshing is performed at the
correct intervals. When self-refreshing is activated from the state in which auto-refreshing is
set, or when exiting standby mode other than through a power-on reset, auto-refreshing is
restarted if the RFSH bit is set to 1 and the RMODE bit is cleared to 0 when self-refresh mode
is cleared. If the transition from clearing of self-refresh mode to the start of auto-refreshing
takes time, this time should be taken into consideration when setting the initial value of
RTCNT. Making the RTCNT value 1 less than the RTCOR value will enable refreshing to be
started immediately.
After self-refreshing has been set, the self-refresh state continues even if the chip standby state
is entered using the LSI standby function, and is maintained even after recovery from standby
mode. Note that the HIZCNT bit in the CMNCR register needs to be set to 1 and pins such as
CKE are driven in standby mode. The self-refresh state cannot be cleared through a manual
reset. In case of a power-on reset, the bus state controller's registers are initialized, and
therefore the self-refresh state is cleared.
Tpw
Tp
Trr
Trc
Trc
Trc
Hi-z
Trc
CKIO
CKE
A25 to A0
CSn
RD/
WR
RASL
,
RASU
DQMxx
D31 to D0
BS
DACKn
*
2
A12/A11
*
1
CASL
,
CASU
Notes: 1. Address pin to be connected to pin A10 of SDRAM.
2. The waveform for
DACKn
is when active low is specified.
Figure 12.30 Self-Refresh Timing
Summary of Contents for HD6417641
Page 2: ...Rev 4 00 Sep 14 2005 Page ii of l...
Page 7: ...Rev 4 00 Sep 14 2005 Page vii of l...
Page 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
Page 12: ...Rev 4 00 Sep 14 2005 Page xii of l...
Page 28: ...Rev 4 00 Sep 14 2005 Page xxviii of l...
Page 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Page 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Page 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Page 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Page 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Page 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Page 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Page 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Page 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Page 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Page 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Page 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Page 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
Page 1032: ...Rev 4 00 Sep 14 2005 Page 982 of 982 REJ09B0023 0400 X X Y data addressing 52 X Y memory 193...
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