DSP56371 View Datasheet(PDF) - Motorola => Freescale
Part Name
Description
Manufacturer
DSP56371 Datasheet PDF : 102 Pages
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Freescale Semiconductor, Inc.
External Clock Operation
8.0 External Clock Operation
The DSP56371 system clock is an externally supplied square wave voltage source connected to EXTAL
(see Figure 1).
EXTAL
.
VIH
Midpoint
VIL
ETH
6
ETL
7
8
ETC
Note: The midpoint is 0.5 (VIH + VIL).
Figure 1 External Clock Timing
Table 5 Clock Operation 150 and 181 MHz Values
150 MHz
181 MHz
No.
Characteristics
Symbol
Min Max Min Max
6 EXTAL input high 1,2
(40% to 60% duty cycle)
7 EXTAL input low1,2
(40% to 60% duty cycle)
8 EXTAL cycle time2
• With PLL disabled
• With PLL enabled
9 Instruction cycle time= ICYC = TC3
• With PLL disabled
• With PLL enabled
Eth
3.33ns 100ns 2.75ns 100ns
Etl
3.33ns 100ns 2.75ns 100ns
Etc
6.66ns
inf
5.52ns
inf
6.66ns 200ns 5.52ns 200ns
Icyc
6.66ns
inf
5.52ns
inf
6.66ns 13.0ns 5.52ns 13.0ns
Note:
1. Measured at 50% of the input transition
2. The maximum value for PLL enabled is given for minimum VCO and maximum MF.
3. The maximum value for PLL enabled is given for minimum VCO and maximum DF.
4. The indicated duty cycle is for the specified maximum frequency for which a part is rated. The
minimum clock high or low time required for correct operation, however, remains the same at lower
operating frequencies; therefore, when a lower clock frequency is used, the signal symmetry may vary
from the specified duty cycle as long as the minimum high time and low time requirements are met.
6
DSP56371 Technical Data
MOTOROLA
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