Datasheet

191
10.4.3 Wait State Control
Wait state insertion during DRAM space access is controlled by setting the TPC, RCD, DWW1,
DWW0, DWR1, and DWR0 bits of the DCR. TPC and RCD are common to both reads and
writes. The timing with waits inserted is shown in figures 10.8 through 10.11. External waits can
be inserted at the time of software waits 2, 3. The sampling location is the same as that of ordinary
space: at one cycle before the T
c2
cycle clock rise. Wait cycles are extended by external waits.
T
p
T
r
T
c1
T
cw1
T
c2
CK
Write
Read
Address
Data
RAS
CASx
RDWR
Data
RDWR
CASx
RAS
Row Column
Figure 10.8 DRAM Bus Cycle (Normal Mode, TPC = 0, RCD = 0, One Wait)