r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 208

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller (BSC)
Rev. 1.00 Sep. 19, 2008 Page 180 of 1270
REJ09B0466-0100
Bit
5
4
3
2
1
0
Bit Name
RLW1
RLW0
SLFRF
TPCS2
TPCS1
TPCS0
0
Initial Value
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Self-Refresh Enable
Description
Refresh Cycle Wait Control
These bits select the number of wait states to be
inserted in a DRAM interface CAS-before-RAS
refresh cycle/synchronous DRAM interface auto-
refresh cycle. This setting applies to all areas
designated as DRAM/continuous synchronous
DRAM space.
00: No wait state inserted
01: 1 wait state inserted
10: 2 wait states inserted
11: 3 wait states inserted
If this bit is set to 1, DRAM/synchronous DRAM
self-refresh mode is selected when a transition is
made to the software standby state. This bit is
valid when the RFSHE bit is set to 1, enabling
refresh operations. It is cleared after recovery from
software standby mode.
0: Self-refreshing is disabled
1: Self-refreshing is enabled
Self-Refresh Precharge Cycle Control
These bits select the number of states in the
precharge cycle immediately after self-refreshing.
The number of states in the precharge cycle
immediately after self-refreshing are added to the
number of states set by bits TPC1 and TPC0 in
DRACCR.
000: [TPC set value] states
001: [TPC set value + 1] states
010: [TPC set value + 2] states
011: [TPC set value + 3] states
100: [TPC set value + 4] states
101: [TPC set value + 5] states
110: [TPC set value + 6] states
111: [TPC set value + 7] states