
2-16
DSP56007/D MOTOROLA
Specifications
External Memory Interface (EMI) DRAM Refresh Timing
EXTERNAL MEMORY INTERFACE (EMI) DRAM REFRESH TIMING
(C
L
= 50pF + 2 TTL Loads)
Table 2-9
External Memory Interface (EMI) DRAM Refresh Timing
No.
Characteristics
Sym.
Timing
Mode
Exp.
50 MHz
66 MHz
88 MHz
Unit
Min Max Min Max Min Max
81 RAS Deassertation to
RAS Assertion
t
RP
slow
fast
1
6
×
T
C
– 7
4
×
T
C
– 7
113
73
—
—
84
—
—
—
61.2
—
—
—
ns
ns
82 CAS Deassertation to
CAS Assertion
T
CPN
slow
fast
1
5
×
T
C
– 7
3
×
T
C
– 7
93
53
—
—
71
—
—
—
49.8
—
—
—
ns
ns
83 Refresh Cycle Time
t
RC
slow
fast
1
13
×
T
C
9
×
T
C
260
180
—
—
197
—
—
—
147.7
—
—
—
ns
ns
84 RAS Assertion Pulse
Width
t
RAS
slow
fast
1
7
×
T
C
– 9
5
×
T
C
– 9
131
91
—
—
97
—
—
—
70.5
—
—
—
ns
ns
85 RAS Deassertation to
RAS Assertion for
Refresh Cycle
2
t
RP
slow
fast
1
5
×
T
C
– 5
3
×
T
C
– 5
95
55
—
—
70
—
—
—
51.8
—
—
—
ns
ns
86 CAS Assertion to RAS
Assertion on Refresh
Cycle
T
CSR
T
C
– 7
13
—
8
—
4.4
—
ns
87 RAS Assertion to CAS
Deassertation on
Refresh Cycle
T
CHR
slow
fast
1
7
×
T
C
– 15
5
×
T
C
– 15
125
85
—
—
91
—
—
—
64.5
—
—
—
ns
ns
88 RAS Deassertation to
CAS Assertion on a
Refresh Cycle
t
RPC
slow
fast
1
5
×
T
C
– 11
3
×
T
C
– 11
89
49
—
—
65
—
—
—
45.8
—
—
—
ns
ns
89 CAS Deassertation to
Data Not Valid
t
OFF
0
0
—
0
—
0
—
ns
Note:
1.
Fast mode is not available for operating frequencies above 50 MHz.
2.
This happens when a Refresh Cycle is followed by an Access Cycle.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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Содержание NXP SYMPHONY DSP56007
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