dsp56371 Freescale Semiconductor, Inc, dsp56371 Datasheet - Page 37

• Manufacturer Part Number: dsp56371
• Description: Dsp56371 Data Sheet
• Manufacturer: Freescale Semiconductor, Inc

9
10
The DSP56371 system clock is an externally supplied square wave voltage source connected to EXTAL
(see
Freescale Semiconductor
Note:
No.
1
2
3
4
5
1
2
3
Figure
See users manual for definition.
DF = Division Factor
Maximum frequency will vary depending on the ordered part number.
Ef = External frequency
MF = Multiplication Factor
PDF = Predivision Factor
FM= Feedback Multiplier
OD = Output Divider
Tc = internal clock period
Comparison Frequency
Input Clock Frequency
Output clock Frequency (with
PLL enabled)
Output clock Frequency (with
PLL disabled)
Duty Cycle
Internal Clocks
External Clock Operation
Note:
4.).
Characteristics
EXTAL
2,3
The midpoint is 0.5 (V
2,3
V
IL
ETH
6
Symbol
IH
FOUT
FOUT
Fref
FIN
+ V
Tc
Tc
—
Figure 4. External Clock Timing
Table 17. INTERNAL CLOCKS
IL
DSP56371 Data Sheet, Rev. 4.1
1
8
).
ETL
13.3
Min
75
40
—
5
7
ETC
(1000/Etc × MF x FM)/
.
(PDF × DF x OD)
1000/Etc
Fref*NR
Typ
50
—
Midpoint
Max
20
60
—
—
UNIT
MHZ
MHZ
MHZ
ns
%
V
IH
where NO is output
FOUT = FVCO/NO
NR is input divider
FVCO=300MHZ
Fref = FN/NR
divider value
Condition
~600MHZ
Internal Clocks
value
—
37