dsp56857 Freescale Semiconductor, Inc, dsp56857 Datasheet - Page 28

• Manufacturer Part Number: dsp56857
• Description: Dsp56857 Digital Signal Controller
• Manufacturer: Freescale Semiconductor, Inc

28
Operating Conditions: V
Frequency of operation (external clock driver)
Clock Pulse Width
External clock input rise time
External clock input fall time
1.
2.
3.
4.
External
Note: The midpoint is V
Clock
Figure 4-8 Connecting a Low Speed External Clock Signal using XTAL
See
External clock input rise time is measured from 10% to 90%.
External clock input fall time is measured from 90% to 10%.
Parameters listed are guaranteed by design.
Figure 4-7
Table 4-5 External Clock Operation Timing Requirements
Characteristic
4
SS
10%
50%
90%
= V
for details on using the recommended connection of an external clock driver.
SSIO
t
PW
IL
3, 4
= V
2, 4
+ (V
SSA
Figure 4-9 External Clock Timing
IH
= 0 V, V
– V
IL
DD
)/2.
56857 Technical Data, Rev. 6
= 1.62-1.98V, V
1
(2-4MHz)
External
t
PW
XTAL
Clock
56857
Symbol
f
t
t
t
osc
PW
rise
DDIO
fall
EXTAL
V
= V
DDA
DDA
/2
= 3.0–3.6V, T
Min
6.25
—
—
0
t
fall
A
= –40° to +120°C, C
Typ
—
—
—
—
t
Freescale Semiconductor
Max
TBD
TBD
rise
240
L
—
≤ 50pF, f
4
10%
50%
op
90%
= 120MHz
V
V
Unit
MHz
IH
IL
ns
ns
ns