HD6417750RF240DV Datasheet, PDF (542/1132 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family / SH7750 Series

Section 13 Bus State Controller (BSC)
SH7750, SH7750S, SH7750R Group
value to set a short refresh request generation interval just while these dummy cycles are being
executed. With simple read or write access, the address counter in the synchronous DRAM used
for auto-refreshing is not initialized, and so the cycle must always be an auto-refresh cycle. After
auto-refreshing has been executed at least the prescribed number of times, a mode register setting
command is issued in the TMw1 cycle by setting MCR.MRSET to 1 and performing a write to
address H'FF900000 + X or H'FF940000 + X.
Synchronous DRAM mode register setting should be executed once only after power-on (reset)
and before synchronous DRAM access, and no subsequent changes should be made.
CKIO
TRp1 TRp2 TRp3 TRp4 TMw1 TMw2 TMw3 TMw4 TMw5
Bank
Precharge-sel
Address
CSn
RD/WR
RAS
CASS
D63–D0
CKE
(High)
Figure 13.42 (1) Synchronous DRAM Mode Write Timing (PALL)
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