No nr nf 1 – Rainbow Electronics W90N740 User Manual
Page 36
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W90N740
- 32 -
INDV [4:0] :PLL input clock divider
Input Divider divides the input reference clock into the PLL.
Input Divider
(NR)
PFD
Feedback
Divider
(NF)
Charge
Pump
VCO
Output
Divider
(NO)
Clock
Divider
&
Selector
EXTAL
ECLKS
OTDV[1:0]
CLKS[2:0]
1
0
PLL
Internal
System
Clock
INDV[4:0]
FBDV[8:0]
48MHz
Gen
480MHz
0
1
USBCKS
USB
Module
FIN
FOUT
GP12
Fig 7.2.6 System PLL block diagram
The formula of output clock of PLL is:
F
OUT
= F
IN
NO
NR
NF
1
∗
∗
F
OUT:
Output clock of Output Divider
F
IN:
External clock into the Input Divider
NR:Input divider value (NR = INDV + 2)
NF:Feedback divider value (NF = FBDV + 2)
NO:Output divider value (NO = OTDV)
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