DE5-NET
User
Manual
65
June 20, 2018
CDCM61004
The FPGA board includes another programmable PLL CDCM61004. The CDCM61004 supports
output frequency range from 43.75 MHz to 683.264 MHz. It provides a parallel interface for
selecting a desired output frequency. The Stratix V GX FPGA's IOs connect to the interface directly.
The differential clock outputs of the CDCM61004 are designed for SFP+ and SATA applications on
FPGA board.
When CDCM61004 is powered on, the default output frequency is 100 MHZ. Users can change the
output frequency by the following control pins:
1.
PR0 and PR1
2.
OD0, OD1, and OD2
3.
RSTN
4.
CE
5.
OS0 and OS1
The following table lists the frequency which CDCM61004 can generate in the FPGA board.
PRESCALLR
DIVIDER
FEEDBACK
DIVIDER
OUTPUT
DEVIDER
OUTPUT
FREQUENCY(MHz)
APPLICATION
4
20
8
62.5
GigE
3
24
8
75
SATA
3
24
6
100
PCI Express
4
20
4
125
GigE
3
24
4
150
SATA
3
25
4
156.25
10 GigE
5
15
2
187.5
12 GigE
3
24
3
200
PCI Express
4
20
2
250
GigE
4
20
2
312.5
XGMII
3
25
1
625
10 GigE
The both values of PRESCALER DIVIDER and FEEDBACK DIVIDER can be specified by the
PR0 and PR1 control pins according to the following table: