Hitachi SH7750 Hardware Manual page 404

Bit 30—Mode Register Set (MRSET): Set when a synchronous DRAM mode register setting is
used. See Power-On Sequence in section 13.3.5, Synchronous DRAM Interface.
Bit 30: MRSET
0
1
Bits 29 to 27—RAS Precharge Time at End of Refresh (TRC2–TRC0)
(Synchronous DRAM: auto- and self-refresh both enabled; DRAM: auto- and self-refresh both
enabled)
Bit 29: TRC2
0
1
Bits 26 to 24, 22, and 18—Reserved: These bits are always read as 0, and should only be written
with 0.
Bit 23—CAS Negation Period (TCAS): This bit is valid only when DRAM interface is set.
Bit 23: TCAS
0
1
Rev. 6.0, 07/02, page 354 of 986
Description
All-bank precharge
Mode register setting
Bit 28: TRC1
0
1
0
1
CAS Negation Period
1
2
Bit 27: TRC0
0
1
0
1
0
1
0
1
RAS Precharge Interval
Immediately after Refresh
0
3
6
9
12
15
18
21
(Initial value)
(Initial value)
(Initial value)