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OPB IPIF user logic

Hi Group, I am designing a simple core to add to the opb bus using opb_ssp0 package. The core has 2 register, and I am tryin to write a value and read from them. But when I do that its giving me an output thats wierd, whenever I write a even number to the register I read back an odd number ( one greater then the even number )but for odd numbers its ok.

have a look at the following code example and the results. /* write to register */ XIo_Out32( (XIo_Address)(XPAR_MY_COUNTER_BASEADDR + REG_A_OFFSET) ,

0x32 ) /*Read from register */ reg_a = XIo_In32( (XIo_Address)XPAR_MY_COUNTER_BASEADDR + REG_A_OFFSET );

/* Display result */ XUartLite_SendByte( XPAR_RS232_BASEADDR, reg_a );

In the above example the result is 0x33.

Does anybody have the same problem ,i will appreciate if somebody could help me to point out the mistake i am doing.

Thanx for your time and support Ram

Reply to
ram
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My first design with EDK had exactly the same problem! The LSB of every register seemed to be stuck at 1... We solved the problem by setting a valid address range for the MIR registers (even if MIR was disabled) and by using a fixed 1 for the IPIF Ack signal (this was ok for our cores, but it is not a good idea in general...).

Good luck, Antonio Di Stefano

P.S. MIR registers have typically an address range

256 byte wide, starting from a 0x------00 address to a 0x------FF one...
Reply to
Antonio Di Stefano

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