Table 21-13 Refresh Controller Bus Timing
Condition A: V
CC
= 2.7 V to 5.5 V, AV
CC
= 2.7 V to 5.5 V, V
REF
= 2.7 V to AV
CC
,
V
SS
= AV
SS
= 0 V, ø = 1 MHz to 8 MHz, T
a
= –20°C to +75°C (regular
specifications), T
a
= –40°C to +85°C (wide-range specifications)
Condition C: V
CC
= 5.0 V ± 10%, AV
CC
= 5.0 V ± 10%, V
REF
= 4.5 V to AV
CC
,
V
SS
= AV
SS
= 0 V, ø = 1 MHz to 16 MHz, T
a
= –20°C to +75°C (regular
specifications), T
a
= –40°C to +85°C (wide-range specifications)
Condition A
Condition C
8 MHz
16 MHz
Test
Item
Symbol
Min
Max
Min
Max
Unit
Conditions
RAS
delay time 1
t
RAD1
—
60
—
30
ns
Figure 21-10
RAS
delay time 2
t
RAD2
—
60
—
30
to
RAS
delay time 3
t
RAD3
—
60
—
30
Figure 21-16
Row address hold time
*
t
RAH
25
—
15
—
RAS
precharge time
*
t
RP
85
—
45
—
CAS
to
RAS
precharge time
*
t
CRP
85
—
45
—
CAS
pulse width
t
CAS
100
—
40
—
RAS
access time
*
t
RAC
—
160
—
85
Address access time
t
AA
—
105
—
55
CAS
access time
*
t
CAC
—
50
—
30
Write data setup time 3
t
WDS3
50
—
15
—
CAS
setup time
*
t
CSR
20
—
15
—
Read strobe delay time
t
RSD
—
60
—
30
Note: At 8 MHz, the times below depend as indicated on the clock cycle time.
t
RAH
= 0.5
×
t
CYC
– 38 (ns)
t
CAC
= 1.0
×
t
CYC
– 75 (ns)
t
RAC
= 2.0
×
t
CYC
– 90 (ns)
t
CSR
= 0.5
×
t
CYC
– 43 (ns)
t
RP
= t
CRP
= 1.0
×
t
CYC
– 40 (ns)
At 16 MHz, the times below depend as indicated on the clock cycle time.
t
RAH
= 0.5
×
t
CYC
– 17 (ns)
t
CAC
= 1.0
×
t
CYC
– 33 (ns)
t
RAC
= 2.0
×
t
CYC
– 40 (ns)
t
CSR
= 0.5
×
t
CYC
– 17 (ns)
t
RP
= t
CRP
= 1.0
×
t
CYC
– 18 (ns)
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