04-07-2010 09:40 PM
i've connected a vhdl design as peripheral to the microblaze using plb in edk.
microblaze writes data to the peripheral through 21 software registers.
this writing alone takes ~350 cycles.
why the data transfer is so much delayed? or is this normal for plb?
how many cycles does PLB take for single write or read operation?
04-07-2010 11:14 PM
Yes, that could be correct. 350/21 is about 17 cycles per register, especially if the instruction cache is not enabled. I thought access to a BRAM on the PLB was about 6 cycles, so that plus an instruction fetch would be about right.