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12. DDR2-SDRAM Interface (DBSC2)
Rev.1.00 Jan. 10, 2008 Page 521 of 1658
REJ09B0261-0100
LV1TH
LV0TH
0
Time
Refresh counter
value
Max. value
(Avera
g
e refresh interval
+ LV1TH)
Level 1
(Refreshin
g
durin
g
request empty cycles)
Level 0
(Refreshin
g
in vacant
periods between
SHwy commands)
Level 2
(Refreshin
g
not done)
Refreshin
g
is done immediately
after auto-refresh is enabled
Refreshin
g
is done in
vacant periods between
SHwy commands
Refreshin
g
is done
durin
g
request
empty cycles
The counter value increments
by the amount of
the avera
g
e refresh interval
Figure 12.7 Relation between Auto-Refresh Operation and Threshold Values
12.5.6
Regarding Address Multiplexing
Memory of various sizes can be connected through the settings of the SDRAM configuration
register (DBCONF). The BWIDTH bits are used to set the external data bus width, and the SPLIT
bit is used to set the size of the memory connected. The BASFT bit setting is used to move the
position of the bank address toward the lower bits; depending on the application the possibility of
page hits may be increased.
Содержание SH7781
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Страница 74: ...2 Programming Model Rev 1 00 Jan 10 2008 Page 44 of 1658 REJ09B0261 0100 ...
Страница 272: ...8 Caches Rev 1 00 Jan 10 2008 Page 242 of 1658 REJ09B0261 0100 ...
Страница 376: ...10 Interrupt Controller INTC Rev 1 00 Jan 10 2008 Page 346 of 1658 REJ09B0261 0100 ...
Страница 694: ...13 PCI Controller PCIC Rev 1 00 Jan 10 2008 Page 664 of 1658 REJ09B0261 0100 ...
Страница 762: ...14 Direct Memory Access Controller DMAC Rev 1 00 Jan 10 2008 Page 732 of 1658 REJ09B0261 0100 ...
Страница 788: ...15 Clock Pulse Generator CPG Rev 1 00 Jan 10 2008 Page 758 of 1658 REJ09B0261 0100 ...
Страница 828: ...17 Power Down Mode Rev 1 00 Jan 10 2008 Page 798 of 1658 REJ09B0261 0100 ...
Страница 846: ...18 Timer Unit TMU Rev 1 00 Jan 10 2008 Page 816 of 1658 REJ09B0261 0100 ...
Страница 1292: ...24 Multimedia Card Interface MMCIF Rev 1 00 Jan 10 2008 Page 1262 of 1658 REJ09B0261 0100 ...
Страница 1326: ...25 Audio Codec Interface HAC Rev 1 00 Jan 10 2008 Page 1296 of 1658 REJ09B0261 0100 ...
Страница 1482: ...28 General Purpose I O Ports GPIO Rev 1 00 Jan 10 2008 Page 1452 of 1658 REJ09B0261 0100 ...
Страница 1538: ...30 User Debugging Interface H UDI Rev 1 00 Jan 10 2008 Page 1508 of 1658 REJ09B0261 0100 ...
Страница 1688: ...Appendix Rev 1 00 Jan 10 2008 Page 1658 of 1658 REJ09B0261 0100 ...
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