I have a usb phy chip sitting on my opb_emc. I always have to use XIo_Out and XIo_In to access. Direct read/write to these addresses doesn't work. My problem is the access time is 100x slower than it should be. Howdo I get down to the access time the chip demands (50 ns)?
Thanks, Clark
Update: I figured out that XIo_In/Out weren't compiling in as macros which caused my write to be very slow. However, I've come across another problem. I have a custom peripheral with dma (based on ipif_common_v1_00_d). I need the dma to just write from one address to another address, i.e. no sinc or dinc. This works fine until I transfer more bytes that the burst setting in the peripheral. Then it's clear that the destination address is being incremented and garbage is being written all over the place.
I tried to disable bursts as per the note:
-- specify the size (must be power of 2) of burst that dma uses to -- tranfer data on the bus, a value of one causes dma to use single -- transactions (burst disabled). -- cep test - disable burst transactions constant DMA_BURST_SIZE : integer := 1;
But when I compile it I get the error: WARNING:Xst:821 - "C:/EDK/hw/XilinxProcessorIPLib/pcores/ipif_common_v1_00_d/hdl/vhdl/dma_sg_p kg.vhd" line 127: Loop body will iterate zero times WARNING:Xst:2096 - "C:/EDK/hw/XilinxProcessorIPLib/pcores/ipif_common_v1_00_d/hdl/vhdl/dma_sg_s im.vhd" line 772: Use of null array slice on signal is not supported. FATAL_ERROR:Xst:Portability/export/Port_Main.h:127:1.16 - This application has discovered an exceptional condition from which it cannot recover. Process will terminate. To resolve this error, please consult the Answers Database and other online resources at
This is a v4fx12 part under edk 8.2.02.
Thanks, Clark
My
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