dsp56167 Freescale Semiconductor, Inc, dsp56167 Datasheet - Page 39

• Manufacturer Part Number: dsp56167
• Description: Advance Information 16-bit Digital Signal Processor
• Manufacturer: Freescale Semiconductor, Inc

EXTERNAL BUS SYNCHRONOUS TIMING
V
Capacitance Derating: The DSP56167 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–D15, PS/DS, RD, WR, BS, PEREN)
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, SSI, and Timer) derate linearly at 1 ns per 5 pF of additional
capacitance from 50 pF to 250 pF of loading. When an internal memory access follows an
external memory access, the PS/DS, R/W, RD, WR, BS, and PEREN strobes remain
deasserted and A0–A15 do not change from their previous state.
MOTOROLA
DD
Num
34
35
36
37
40
41
42
43
44
45
46
47
48
49
50
51
= 5.0 V 10%; T
CLK in (EXTAL) High to CLKO High
CLKO High to
BS Width Deassertion
CLKO High to WR Assertion Low
CLKO High to BS Deassertion
a.TA Assertion to CLKO High (Setup)
b.TA Deassertion to CLKO High (Setup)
a. CLKO High to TA Assertion (Hold)
b. CLKO High to TA Deassertion (Hold)
CLKO High to D0–D15 Out Valid
CLKO High to D0–D15 Out Invalid (Hold)
D0–D15 In Valid to CLKO Low (Setup)
CLKO Low to D0–D15 In Invalid (Hold)
CLKO Low to
a. WR Hold Time from CLKO Low
b. RD Hold Time from CLKO Low
CLKO High to D0–D15 tri-stated
CLKO High to D0–D15 Out Active
CLKO High to
a. A0–A15 Valid
b. PS/DS, PEREN Assertion, R/W Valid
c. BS Assertion
d. RD Assertion
a. WR Deassertion
b. RD Deassertion
a. A0–A15 Invalid
b. PS/DS, PEREN, R/W Invalid
J
= –40 to +115˚C; C
Table 2-8 External Bus Synchronous Timing
Characteristics
DSP56167/D, Rev. 1
L
= 50 pF + 1 TTL load
External Bus Synchronous Timing
T + 4.0
Min
14.6
2.2
6.5
6.5
2.0
2.0
4.0
4.0
0.0
1.0
1.0
—
—
—
—
—
—
—
—
—
0
0
0
60 MHz
T + 6.0
Max
10.0
4.0
4.0
4.0
4.0
7.4
3.0
3.0
4.0
8.0
—
—
—
—
—
—
—
—
—
—
—
—
—
Specifications
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
2-13