USRP question: Writing to AD9862 registers from FPGA?


#1

Hi gnuradiators,

I know I can use the usrper program to write values to the registers of
the two
9862 chips (on the USRP1). I am using the USRP1 for a custom
application, with
my own FPGA code. My question is whether it is possible for the FPGA to
write
values to these registers directly? Or is it only the cypress
microcontroller
that has access to these registers? And if so, is it possible for the
FPGA to
command the microcontroller to do so?

I didn’t find any obvious verilog module that does this when looking
through the
original verilog code. If it exists and I missed it, please let me know.

Thank you,
Aviv Keshet


#2

On Wed, Jun 03, 2009 at 10:28:55PM -0400, Aviv Keshet wrote:

Hi gnuradiators,

I know I can use the usrper program to write values to the registers of the two
9862 chips (on the USRP1). I am using the USRP1 for a custom application, with
my own FPGA code. My question is whether it is possible for the FPGA to write
values to these registers directly?

No, there are no wires that connect these.

Or is it only the cypress microcontroller that has access to these registers?

yes.

And if so, is it possible for the FPGA to command the microcontroller to do so?

no.

I didn’t find any obvious verilog module that does this when looking through the
original verilog code. If it exists and I missed it, please let me know.

Thank you,
Aviv Keshet

FYI, on the USRP2 everything connects to the FPGA :wink:

Eric