HD6412332 RENESAS [Renesas Technology Corp], HD6412332 Datasheet - Page 212

• Manufacturer Part Number: HD6412332
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Self-Refreshing: A self-refresh mode (battery backup mode) is provided for DRAM as a kind of
standby mode. In this mode, refresh timing and refresh addresses are generated within the DRAM.
To select self-refreshing, set the RFSHE bit and RMODE bit in DRAMCR to 1. When a SLEEP
instruction is executed to enter software standby mode, the CAS and RAS signals are output and
DRAM enters self-refresh mode, as shown in figure 6.27.
When software standby mode is exited, the RMODE bit is cleared to 0 and self-refresh mode is
exited.
If a CBR refresh request occurs when making a transition to software standby mode, CBR
refreshing is executed, then self-refresh mode is entered.
Rev.4.00 Sep. 07, 2007 Page 182 of 1210
REJ09B0245-0400
CS
CAS, LCAS
HWR (WE)
Note: n = 2 to 5
φ
n
(RAS)
T
Rp
Figure 6.27 Self-Refresh Timing
T
Rcr
High
Software
standby
T
Rc3