DSP56362UM Ver la hoja de datos (PDF) - Freescale Semiconductor
Número de pieza
componentes Descripción
fabricante
DSP56362UM Datasheet PDF : 152 Pages
| |||
EXTERNAL CLOCK OPERATION
3.7 EXTERNAL CLOCK OPERATION
The DSP56362 system clock is an externally supplied square wave voltage source connected to EXTAL
(Figure 3-1)
EXTAL
VILC ETH 2
5
CLKOUT With
PLL Disabled
ETL
3
4
ETC
CLKOUT With
PLL Enabled
Midpoint
VIHC
5
7
6a
6b
7
Note: The midpoint is 0.5 (VIHC + VILC).
Figure 3-1 External Clock Timing
AA0459
Table 3-5 Clock Operation 100 and 120 MHz Values
No.
Characteristics
Symbol
100 MHz
Min
Max
120 MHz
Min
Max
1 Frequency of EXTAL (EXTAL Pin Frequency)
The rise and fall time of this external clock should be 3 ns
maximum.
2 EXTAL input high1, 2
• With PLL disabled (46.7%–53.3% duty cycle)3
• With PLL enabled (42.5%–57.5% duty cycle)3
3 EXTAL input low1, 2
• With PLL disabled (46.7%–53.3% duty cycle)3
• With PLL enabled (42.5%–57.5% duty cycle)3
4 EXTAL cycle time2
• With PLL disabled
• With PLL enabled
Ef
0
100.0
0
120.0
ETH
4.67 ns
∞
0.00 ns
∞
4.25 ns 157.0 µs 0.00 ns 157.0 µs
ETL
4.67 ns
∞
4.67 ns
—
4.25 ns 157.0 µs 4.25 ns 1570.00
ETC
10.00 ns ∞
8.33 ns
—
10.00 ns 273.1 µs 8.33 ns 273.1 µs
5 CLKOUT change from EXTAL fall with PLL disabled
4.3 ns 11.0 ns
DSP56362 Technical Data, Rev. 4
Freescale Semiconductor
3-5
Share Link: 