10 SDRAM CONTROLLER (SDRAMC)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
10-17
SDRAM Configuration Register (SDRAMC_CFG)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
SDRAM
Configuration
Register
(SDRAMC_CFG)
0x302204
(32 bits)
D31–14 –
reserved
–
–
–
0 when being read.
D13–12 T24NS[1:0] Number of SDRAM t
RP
and t
RCD
cycles
T24NS[1:0]
# of cycles
0x0 R/W
0x3
0x2
0x1
0x0
4 cycles
3 cycles
2 cycles
1 cycle
D11
–
reserved
–
–
–
0 when being read.
D10–8 T60NS[2:0] Number of SDRAM t
RAS
cycles
T60NS[2:0]
# of cycles
0x0 R/W
0x7
0x6
:
0x1
0x0
8 cycles
7 cycles
:
2 cycles
1 cycle
D7–4 T80NS[3:0] Number of SDRAM t
RC
, t
RFC
and
t
XSR
cycles
T80NS[3:0]
# of cycles
0xe R/W
0xf
0xe
:
0x1
0x0
16 cycles
15 cycles
:
2 cycles
1 cycle
D3
–
reserved
–
–
–
0 when being read.
D2–0 ADDRC[2:0] SDRAM address configuration
ADDRC[2:0]
Configuration 0x0 R/W Do not set to 0x4.
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
512M bits
128M bits x 2
64M bits x 2
reserved
256M bits
128M bits
64M bits
16M bits
D[31:14] Reserved
D[13:12] T24NS[1:0]: Number of SDRAM t
RP
and t
RCD
Cycles Bits
Sets the t
RP
and t
RCD
SDRAM timing parameters.
• t
RP
PRECHARGE to ACTIVE command period
• t
RCD
ACTIVE to READ/WRITE delay time
7.3
Table 10.
t
RP
and t
RCD
Settings
T24NS[1:0]
t
RP
, t
RCD
0x3
4 cycles
0x2
3 cycles
0x1
2 cycles
0x0
1 cycle
(Default: 0x0)
D11
Reserved
D[10:8] T60NS[2:0]: Number of SDRAM t
RAS
Cycles Bits
Sets the t
RAS
SDRAM timing parameter.
• t
RAS
ACTIVE to PRECHARGE command period
7.4
Table 10.
t
RAS
Settings
T60NS[2:0]
t
RAS
0x7
8 cycles
0x6
7 cycles
:
:
0x1
2 cycles
0x0
1 cycle
(Default: 0x0)
D[7:4]
T80NS[3:0]: Number of SDRAM t
RC
, t
RFC
, and t
XSR
Cycles Bits
Sets the t
RC
, t
RFC
and t
XSR
SDRAM timing parameters.
• t
RC
ACTIVE to ACTIVE command cycle time
• t
RFC
Auto-refresh cycle time
• t
XSR
Self-refresh end to ACTIVE command period