Bdale Garbee wrote: > Looking at options for locking all the clocks that are part of the EME > station I'm building to my HP 58503A GPS-synced clock. Searching the > list archives, I found this note from Matt regarding the external clock > input on the USRP: > > http://lists.gnu.org/archive/html/discuss-gnuradio/2005-03/msg00030.html > > Has anyone played with this? > > Of particular interest is whether anyone has hacked the FPGA code to use > the internal PLLs to retain a 64 Mhz sample clock using a 10 Mhz > reference clock input to the board.
There are a couple of problems here. First, the PLLs in the PFGA are extremely noisy, and are only useful for digital clocks. But even if they weren't, the ADC/DAC chips are hooked directly to the input clock, so the FPGA can't drive those lines. Are you sure you need a 64 MHz sample clock for your app? Matt _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
