ni579x FPGA Self Synchronization
- 更新时间2023-02-17
- 阅读时长2分钟
ni579x FPGA Self Synchronization
Use this synchronization method in conjunction with ni579x FPGA Align on the FPGA to synchronize the FPGAs.
Inputs/Outputs
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Default value: No error
sync.cptr.period
The period, in clocks, of the Common Periodic Time Reference (CPTR). The CPTR period controls the rate at which synchronized signals are realized. This parameter is required, and you must specify a value for each target to be synchronized.
When using ni579x FPGA Align, the CPTR period must be the same as the Reference Clock period. The sync.cptr.period must be set to the ratio of the clock-driven logic (CDL) rate (that the Align node is in) to the sync.meas.Reference Clock rate. For example, the CPTR period must be 13 if you are using
PXI_Clk10 for the Reference Clock, and the
IO Module\Sample Clock for the CDL clock (130 MHz / 10 MHz). When using ni579x Host Align, this value is configurable. The maximum value is
63. The minimum value for sync.cptr.period must be large enough to ensure transmission across the sync.cptr.FPGA I/O line. Refer to the specifications for the FPGA I/O line that you choose. For example, if the FPGA I/O line has a maximum propagation delay of 50 ns, the minimum value is
7 (the period of the 130 MHz IO Module\Sample Clock is approximately 7.692 ns, so 7 clocks are required to exceed 50 ns). NI does not recommend changing the CPTR period on-the-fly. Alignment must be re-run if you change the CPTR period.
error out
Error information.
The node produces this output according to standard error behavior.