dsp56002fc80 Freescale Semiconductor, Inc, dsp56002fc80 Datasheet - Page 55

• Manufacturer Part Number: dsp56002fc80
• Description: 24-bit Digital Signal Processor
• Manufacturer: Freescale Semiconductor, Inc

EXTERNAL BUS SYNCHRONOUS TIMING
C
Capacitance Derating: The DSP56002 external bus timing specifications are designed and tested
at the maximum capacitive load of 50 pF, including stray capacitance. Typically, the drive
capability of the external bus pins (A0–A15, D0–D23, PS, DS, RD, WR, X/Y) derates linearly at 1
ns per 12 pF of additional capacitance from 50 pF to 250 pF of loading. Port B and C pins (HI,
SCI, SSI, and Timer) derate linearly at 1 ns per 5 pF of additional capacitance from 50 pF to 250
pF of loading. Active-low lines should be “pulled up” in a manner consistent with the ac and dc
specifications.
MOTOROLA
Num
Notes:
L
140 First CKOUT transition to Address Valid
141 Second CKOUT transition to WR
142 Second CKOUT transition to WR
143 Second CKOUT transition to RD
144 Second CKOUT transition to RD
145 First CKOUT transition to Data-Out Valid
146 First CKOUT transition to Data-Out
147 Data-In Valid to second CKOUT transition
148 Second CKOUT transition to Data-In
149 First CKOUT transition to Address
= 50 pF + 2 TTL loads
Assertion
Deassertion
Assertion
Deassertion
Invalid
(Setup)
Invalid (Hold)
Invalid
1.
2.
3.
4.
5.
•
•
AC timing specifications which are referenced to a device input signal are measured in production
with respect to the 50% point of the respective input signal’s transition.
WS are wait state values specified in the BCR.
First CKOUT transition to data-out invalid (specification # T146) and first CKOUT transition to
address invalid (specification # T149) indicate the time after which data/address are no longer
guaranteed to be valid.
Timings are given from CKOUT midpoint to V
First CKOUT transition is a falling edge of CKOUT for CKP = 0.
3
3
WS = 0
WS > 0
1
Characteristics
Table 2-13 External Bus Synchronous Timing
DSP56002/D, Rev. 3
Min
1.3
3.4
—
—
—
—
—
0
0
0
0
40 MHz
OL
T
or V
H
Max
6.2
4.4
9.1
3.9
3.4
5.4
—
—
—
—
+ 4.4
OH
of the corresponding pin(s).
Min
3.4
External Bus Synchronous Timing
—
—
—
—
–3
—
1
0
0
0
66 MHz
T
Max
H
3.9
4.5
—
—
—
—
5
4
5
3
+ 4
Min
3.4
—
—
—
—
–3
—
1
0
0
0
80 MHz
Specifications
T
Max
H
3.9
4.5
—
—
—
—
4
5
3
5
+ 4
Unit
2-29
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns