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Honored Contributor
Honored ContributorHow to Connect to SOPC Avalong Bus from outside of SOPC
I'm using the SDRAM with Nios and SOPC, but I also need to write to the SDRAM via logic that is outside the SOPC. How is this typically done? I'm assuming I would need to create a peripheral ...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- It is easier to create a component with an Avalon master interface if you intend to share the RAM between your custom logic and other components (such as the Nios CPU). I understood from your first post that this is what you wanted to do. SOPC builder will automatically create arbitration logic for you to share the RAM, which would be a bit more difficult to do if you had to do it yourself. --- Quote End --- Gotcha.. yes that's the goal. BTW, anyone know how fast I can clock the data in from my user logic to the avalon sopc ram? All the sopc devices ( cpu, ram, etc) are running off 100mhz.. and my user logic writes 4 bytes every 50mhz. The simple write master is configured for a 256 byte fifo. Unfortunately, when I look at the memory after a second of transfers, it looks bad. It only works when I slow the writes ***WAY**** down. I haven't played with it to see at what speed it starts to go bad, but obviously writing a single 32bit word at speeds anywhere near the avalon sopc speed doesn't work. Anyone else experience such a thing, or have an idea what's going on?
