D12320VF25IV Datasheet, PDF (1142/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Appendix B Internal I/O Registers
DRAMCR—DRAM Control Register
(Not supported in H8S/2321)
H'FED7
Bus Controller
Bit
:
Initial value :
Read/Write :
7
RFSHE
0
R/W
6
RCW
0
R/W
5
RMODE
0
R/W
4
CMF
0
R/W
3
CMIE
0
R/W
2
CKS2
0
R/W
1
CKS1
0
R/W
0
CKS0
0
R/W
Refresh Counter Clock Select
0 0 0 Count operation disabled
1 Count uses φ/2
1 0 Count uses φ/8
1 Count uses φ/32
1 0 0 Count uses φ/128
1 Count uses φ/512
1 0 Count uses φ/2048
1 Count uses φ/4096
Compare Match Interrupt Enable
0 Interrupt request (CMI) by CMF flag disabled
1 Interrupt request (CMI) by CMF flag enabled
Compare Match Flag
0 [Clearing condition]
When 0 is written to CMF after reading CMF = 1
[Setting condition]
1 When RTCNT = RTCOR
Refresh Mode
0 Self-refreshing is not performed in software standby mode
1 Self-refreshing is performed in software standby mode
RAS-CAS Wait
0 Wait state insertion in CAS-before-RAS refreshing disabled
RAS falls in T_r cycle
1 One wait state inserted in CAS-before-RAS refreshing
RAS falls in T_c1 cycle
Refresh Control
0 Refresh control is not performed
1 Refresh control is performed
Rev.6.00 Sep. 27, 2007 Page 1110 of 1268
REJ09B0220-0600