On Fri, Sep 04, 2009 at 05:01:59PM -0400, Bruce McGuffin wrote: > Matt Ettus wrote: >> Bruce McGuffin wrote: >> >>> Hi >>> >>> When I specify a particular receiver decimation rate >>> for the USRP2, the task of decimating is presumably >>> split up between the CIC and two half-band filters. >>> My question is how is the task split up, >>> and where in the code does this happen? >>> >> >> If the requested decimation rate is a multiple of four, we use the two >> halfband filters, and the rest is CIC. If it is only a multiple of >> two, we use one halfband filter and the rest in CIC. If it is an odd >> number, we use only CIC. >> >> Matt >> > When the decimation rate is divisible by 2 but not 4, which half-band > filter do you use? > And where in the code is this decision made? > > Bruce
Hi Bruce! The decision is made in the firmware. See usrp2/firmware/apps/app_common_v2.c line 247, in the function config_rx_v2_cmd. The actual control register (dsp_rx_regs->decim_rate) is written on line 265. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
