SH7751 Datasheet, PDF (546/1224 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

13. Bus State Controller (BSC)
RTCNT value
RTCOR-1
RTCNT cleared to 0 when
RTCNT = RTCOR
H'00000000
RTCSR.CKS2–0
= 000 ≠ 000
Refresh
request
External bus
Refresh request cleared
by start of refresh cycle
Auto-refresh cycle
Figure 13.35 Auto-Refresh Operation
Time
CKIO
TRr1 TRr2 TRr3 TRr4 TRrw TRr5 Trc Trc Trc
CSn
RD/WR
RAS
CASS
DQMn
D31–D0
BS
CKE
Figure 13.36 Synchronous DRAM Auto-Refresh Timing
Rev.4.00 Oct. 10, 2008 Page 448 of 1122
REJ09B0370-0400