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RFNoC multiplier input width

NF
Nick Foster
Tue, Sep 1, 2015 11:23 PM

Quick technical question about lib/rfnoc/mult.v. Why is lib/rfnoc/mult.v
set up with the DSP48E instantiated as:

.A({5'b0, A_IN})

? (line 73). I've been wondering where my five top bits went. I can work
around it, but there's probably some good reason here I'm missing.

Thanks!
Nick

Quick technical question about lib/rfnoc/mult.v. Why is lib/rfnoc/mult.v set up with the DSP48E instantiated as: .A({5'b0, A_IN}) ? (line 73). I've been wondering where my five top bits went. I can work around it, but there's probably some good reason here I'm missing. Thanks! Nick
ME
Matt Ettus
Wed, Sep 2, 2015 11:21 PM

Those top 5 bits are not used for multiplication, only for other functions
of the DSP48E.

On Tue, Sep 1, 2015 at 4:23 PM, Nick Foster via USRP-users <
usrp-users@lists.ettus.com> wrote:

Quick technical question about lib/rfnoc/mult.v. Why is lib/rfnoc/mult.v
set up with the DSP48E instantiated as:

.A({5'b0, A_IN})

? (line 73). I've been wondering where my five top bits went. I can work
around it, but there's probably some good reason here I'm missing.

Thanks!
Nick


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Those top 5 bits are not used for multiplication, only for other functions of the DSP48E. On Tue, Sep 1, 2015 at 4:23 PM, Nick Foster via USRP-users < usrp-users@lists.ettus.com> wrote: > Quick technical question about lib/rfnoc/mult.v. Why is lib/rfnoc/mult.v > set up with the DSP48E instantiated as: > > .A({5'b0, A_IN}) > > ? (line 73). I've been wondering where my five top bits went. I can work > around it, but there's probably some good reason here I'm missing. > > Thanks! > Nick > > _______________________________________________ > USRP-users mailing list > USRP-users@lists.ettus.com > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com > >