Refresh rpc delay, Refresh ras pulse width, Number of ras precharge cycles – Epson S1C33210 User Manual
Page 178: Cas cycle control, Ras cycle control
II CORE BLOCK: BCU (Bus Control Unit)
B-II-4-26
EPSON
S1C33210 FUNCTION PART
Refresh RPC delay
Use RPC0 to set the RPC delay value of a refresh cycle (a delay time from the immediately preceding precharge
to the fall of #CAS).
RPC0 = "1": 2 cycles
RPC0 = "0": 1 cycle
Refresh RAS pulse width
Use RRA to set the #RAS pulse width of a CAS-before-RAS refresh cycle.
Table 4.17 Refresh RAS Pulse Width
RRA1
RRA0
Pulse width
1
1
5 cycles
1
0
4 cycles
0
1
3 cycles
0
0
2 cycles
The initial default value is 2 cycles.
Number of RAS precharge cycles
Use RPRC to choose the number of RAS precharge cycles.
Table 4.18 Number of RAS Precharge Cycles
RPRC1
RPRC0
Number of cycles
1
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
0
1 cycle
The initial default value is 1 cycle.
CAS cycle control
Use CASC to choose the number of CAS cycles when accessing DRAM.
Table 4.19 Number of CAS Cycles
CASC1
CASC0
Number of cycles
1
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
0
1 cycle
The initial default value is 1 cycle.
RAS cycle control
Use RASC to choose the number of RAS cycles when accessing DRAM.
Table 4.20 Number of RAS Cycles
RASC1
RASC0
Number of cycles
1
1
4 cycles
1
0
3 cycles
0
1
2 cycles
0
0
1 cycle
The initial default value is 1 cycle.