Re: [partial-reconfig] Write/Read data on SRAM

["Paolo Furia" <paolo.furia@xxxxxxxxx>]

I solved the problem declaring buf and val as Xuint8. I forgot to
close this answer; thanks anyway for your help.

Regards,
Paolo Furia

2008/8/29, Nathan Hillery <nhillery1@xxxxxxxxx>:
> Your values are being sign-extended, as if they are treated as signed
> integers. Try changing "char" to "unsigned char" in the definition of
> buf.
>
>
> On 8/28/08, Paolo Furia <paolo.furia@xxxxxxxxx> wrote:
>> Hi all,
>> I'm trying to write data (a partial bitstream) on SRAM and then read them.
>> I'm working on a ML402 (with a virtex-4 fpga) and I send the data through
>> RS232. I've a Microblaze on my system that manage all.
>> I use the following C code:
>>
>>
>> /* BITSTREAM_BASEADDR is the base address of SRAM */
>>
>>      char buf, val;
>>      int i;
>>      Xuint32 baseaddr = BITSTREAM_BASEADDR;
>>
>>      for (i=0; i<50492; i++){
>>
>>         buf = XUartLite_RecvByte(UART_BASEADDR);
>>
>>         XIo_Out8((baseaddr+i), buf);
>>
>>         }
>>
>>
>>         xil_printf("Bitstream stored!\n\r");
>>
>>
>>         xil_printf("High address: %d\n\r", (baseaddr+i));
>>
>>
>>         /***** Cycle to read the first 10 values stored *****/
>>
>>         xil_printf("value: %x\n\r\n\r", val);
>>
>>         xil_printf("\n Primi 10 valori salvati:\n\r\n");
>>
>>         for (i=0; i<10; i++){
>>
>>         val = XIo_In8((BITSTREAM_BASEADDR+i));
>>
>>         xil_printf("valore: %x\n\r\n\r", val);
>>
>>         }
>>
>>         /***** End of cycle *****/
>>
>>
>>
>> The first 10 values of the file I send are: FF FF FF FF 55 99 AA 66 04 00.
>> But Microblaze reads from memory this: FFFFFFFF, FFFFFFFF, FFFFFFFF,
>> FFFFFFFF, 55, FFFFFF99, FFFFFFAA, 66, 4, 0.
>> I tried sending other values and I discovered that alla values between 0
>> and
>> 127 are displayed well, while the values from 128 to 255 are dysplayed
>> with
>> FFFFFF ahead. Why? Do you have any suggestion? I'd very appreciate any
>> help.
>>
>> Regards,
>>
>> Paolo Furia
>>
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