Depending on FPGA technology the physical layer uses different
deserialization factors and corresponding clock division factors to
divide the source synchronous interface clock. This must be
exposed to software so it can act on it while setting the DDS rate.
Xilinx CMOS clock ratio - 4
Xilinx LVDS clock ratio - 4
Intel CMOS clock ratio - 1
If Tx source synchronous clock is not routed through clock capable pins
the interface and driving logic must run on the Rx interface clock.
This introduces a dependency, Rx interface must be bring up before the
Tx. In this mode a Tx only operation is not possible.
This is done through a synthesis parameter.
Expose this parameter to the software so it can query if the limitations
exists in the implementation.
ADRV9001 interfacing IP supports the following modes on Xilinx devices:
A B C D E F G H
CSSI__1-lane 1 32 80 80 2.5 SDR 8
CSSI__1-lane 1 32 160 80 5 DDR 4
CSSI__4-lane 4 8 80 80 10 SDR 2
CSSI__4-lane 4 8 160 80 20 DDR 1
LSSI__1-lane 1 32 983.04 491.52 30.72 DDR 4
LSSI__2-lane 2 16 983.04 491.52 61.44 DDR 2
Columns description:
A - SSI Modes
B - Data Lanes Per Channel
C - Serialization factor Per data lane
D - Max data lane rate(MHz)
E - Max Clock rate (MHz)
F - Max Sample Rate for I/Q (MHz)
G - Data Type
H - DDS Rate
CSSI - CMOS Source Synchronous Interface
LSSI - LVDS Source Synchronous Interface
Intel devices supports only CSSI modes.
Laszlo Nagy
stefan.raus
Istvan Csomortani