Page 52
Epson Research and Development
Vancouver Design Center
S1D13504
Hardware Functional Specification
X19A-A-002-19
Issue Date: 01/11/06
7.3.4 EDO-DRAM CAS Before RAS Refresh Timing
Figure 7-10: EDO-DRAM CAS Before RAS Refresh Timing
Table 7-10: EDO-DRAM CAS Before RAS Refresh Timing
Symbol
Parameter
Min Typ
Max
Units
t1
Memory clock period
25
ns
t2
RAS# to CAS# precharge time (REG[22h] bits [3:2] = 00)
1.45 t1
ns
RAS# to CAS# precharge time (REG[22h] bits [3:2] = 01 or 10)
0.45 t1
ns
t3
Random read or write cycle time (REG[22h] bits [6:5] = 00)
5 t1
ns
Random read or write cycle time (REG[22h] bits [6:5] = 01)
4 t1
ns
Random read or write cycle time (REG[22h] bits [6:5] = 10)
3 t1
ns
t4
CAS# precharge time (REG[22h] bits [3:2] = 00)
2 t1
ns
CAS# precharge time (REG[22h] bits [3:2] = 01 or 10)
1 t1
ns
t5
CAS# setup time (REG[22h] bits [3:2] = 00 or 10)
0.45 t1 - 2
ns
CAS# setup time (REG[22h] bits [3:2] = 01)
1 t1 - 2
ns
t6
RAS# precharge time (REG[22h] bits [3:2] = 00)
2 t1 - 1
ns
RAS# precharge time (REG[22h] bits [3:2] = 01)
1.45 t1 - 1
ns
RAS# precharge time (REG[22h] bits [3:2] = 10)
1 t1 - 1
ns
RAS#
CAS#
t4
t6
t5
t2
t3
t1
Memory
Clock