
Specifications
External Memory Interface (EMI) SRAM Timing
MOTOROLA
DSP56007/D 2-17
EXTERNAL MEMORY INTERFACE (EMI) SRAM TIMING
(C
L
= 50pF + 2 TTL Loads)
Figure 2-12 CAS before RAS Refresh Cycle
Table 2-10
External Memory Interface (EMI) SRAM Timing
No.
Characteristics
Symbol
Expression
50 MHz
66 MHz
88 MHz
Unit
Min Max Min Max Min Max
91 Address Valid and CS
Assertion Pulse Width
t
RC
, t
WC
4
×
T
C
– 11 +
Ws
×
T
C
69
—
50
—
34.5
—
ns
92 Address Valid to RD or WR
Assertion
t
AS
T
C
+ T
L
– 13
17
—
10
—
4.4
—
ns
93 RD or WR Assertion Pulse
Width
t
WP
2
×
T
C
– 5 +
Ws
×
T
C
35
—
23
—
17.7
—
ns
94 RD or WR Deassertation to
RD or WR Assertion
—
2
×
T
C
– 11
29
—
19
—
11.7
—
ns
95 RD or WR Deassertation to
Address not Valid
t
WR
T
H
– 6
4
—
2
—
0.1
—
ns
96 Address Valid to Input Data
Valid
t
AA
, t
AC
3
×
T
C
+ T
L
–15 +
Ws
×
T
C
—
55
—
38
—
24.8
ns
97 RD Assertion to Input Data
Valid
t
OE
2
×
T
C
– 15 +
Ws
×
T
C
—
25
—
15
—
7.7
ns
98 RD Deassertation to Data
Not Valid (Data Hold Time)
t
OHZ
0
0
—
0
—
0
—
ns
MRAS
MCAS
Data In
MD0–MD7
83
81
84
85
88
82
87
89
86
AA0266
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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