pci target help

pci target help

Postby Mr.Cod » Wed Nov 10, 2004 10:33 am

When I use a 32bits x 16locations ram in a pci target I chose 0x200 - 0x23f space address. If I want to write at location1 I must to write on address pci bus the address 0x204???? (1 location is 32bits ==> 4 bytes address)...It is correct?
If I use a fifo with portin(for write) and portout(for read) , 32bits x 16 locations too, I mapped at 0x200-0x23f. When I write in fifo through pci bus I write always the same address on pci address bus????? :idea:

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Postby fpga4fun » Wed Nov 10, 2004 4:33 pm

Yes, in my example RAM, address 1 of the 32 bits RAM starting at 0x200 would be at 0x204. That's because I didn't make the RAM 8-bits addressable, only 32-bits. Otherwise you would be able to go to address 0x201 for example and read or write just one byte.

If you use a FIFO, you typically access it through a single address, that’s correct.
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Postby Stijena » Mon Aug 22, 2005 11:59 pm

Is the verilog code the same if we read/write to the memory as the MEMORY, not I/O. Is there anything else to change except the command code on the BE lines during command phase?

Thanks in advance
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