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Altera_Forum
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11 years ago

BFM Read from On Chip RAM

I followed D. W. Hawkins (dwh@ovro.caltech.edu) tutorial on JTAG-to-Avalon-MM. There is a task in the tutorial that reads a slave address using the BFM master. The slave is onchip_ram. The problem is...
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Altera_Forum
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11 years ago

Thanks a lot Mr. Hawkins for the reply. I went through the other thread before posting here. In the example qsys_vip that you have posted, you have a BFM slave module in QSys. I have a RAM slave module. I see that you are setting slave response latency like this: 

`SLAVE.set_response_latency(2, 0);

In my case, I know the latency of the RAM ahead of time (you can set it in QSys parameters, can be 1 or 2 clock cycles). I just need to tell the BFM master to wait for it. I went through the "Altera Verification IP Guide" and couldn't find which API sets the master wait time. I found this one: 

get_response_wait_time()
Returns the wait latency for transaction in the response descriptor that has been
removed from the response queue. Each cycle in a burst has its own wait latency
entry.

This RAM transaction is a read transactions with no readdatavalid signal:

https://www.alteraforum.com/forum/attachment.php?attachmentid=10160

I assume when you get the value of get_response_wait_time() from slave BFM, you have to send it to the master BFM. What is the API for the master BFM to know about this wait time?