r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 293

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

6.8.13
This LSI is provided with a synchronous DRAM refresh control function. Auto refreshing is used.
In addition, self-refreshing can be executed when the chip enters the software standby state.
Refresh control is enabled when any area is designated as continuous synchronous DRAM space
in accordance with the setting of bits RMTS2 to RMTS0 in DRAMCR.
Precharge-sel
DQMU, DQML
Address bus
Refresh Control
Data bus
CKE
CAS
RAS
WE
Figure 6.65 Example of Operation Timing in RAS Down Mode
φ
PALL ACTV READ
Continuous synchronous
DRAM space read
Column
address
T
p
address
address
Row
Row
T
r
(BE = 1, CAS Latency 2)
T
c1
Column address
T
cl
T
c2
High
NOP
External
space read
External address
External address
T
1
Rev. 1.00 Sep. 19, 2008 Page 263 of 1342
T
2
READ
Continuous synchronous
DRAM space read
T
Section 6 Bus Controller (BSC)
c1
Column address 2
T
cl
NOP
REJ09B0467-0100
T
c2