Reading and writing from/to VME device
Didier Kryn
kryn at in2p3.fr
Mon Apr 2 19:15:05 EST 2007
Konstantin, I reproduced your ioctl() problem with the attached
program. The conclusion is that the only valid size and base parameters
for A16 are windowSizeL=0x10000 and xlatedAddrL=0. This means the A16
space can only be mapped as a whole. What you observed with
xlatedAddrL=0x10100000 is that the ioctl(), gently masks the irrelevant
high order bits.
Best regards.
Didier
Didier Kryn a écrit :
>
>
> Now, for the ioctl problem, Konstantin, did you try to set
> xlatedAddrL to zero. The Tsio148, and therefore the driver, enforce
> alignment on rather big blocks and maybe misalignment is the cause of
> the "invalid argument" error. I see no reason not to map the entire
> A16, A24 or CR/CSR spaces. For the others, of course, you are limited
> by the size of the cpu's address space.
>
> I will eventually try to reproduce your ioctl problem next week.
> Hopping you will solve it before :-) .
>
> Best regards. Didier
>
> Konstantin Boyanov said:
>> Hi again,
>>
>> Thank you once again for presenting the VME world to me :)
>>
>> >Looks like you're reading something. Address 0x10100000 is larger than
>> >a 24 bit address. Perhaps you should be using A32 transfers instead of
>> >A24?
>>
>> No, no, I need to do A16 access, thats the only way to read the
>> control registers. Form here comes also my confusion - I thought that
>> when I'm reading CS/CSR register I need to do it in CSR address
>> space. So no algorithms for geographical location of boards are
>> needed in my case I guess.
>> Actually the base address of CSR on the board is 0xA000 (10100000 is
>> the first byte of the address selection in inary, shame on me :( ).
>> But when I try to configure it with outWinCfgADC.zlatedAddrL =
>> 0xA000, when I run the programm I get an errno 29 (Invalid argument)
>> from ioctl(). In fact if I set the xlatedAddrL to some value smaller
>> that 0x10000 I get this error. Here's my most recent configuration:
>>
>> outWinCfgADC.windowNbr = 0;
>> outWinCfgADC.windowEnable = 1;
>> outWinCfgADC.wrPostEnable = 0;
>> outWinCfgADC.userAccessType = VME_SUPER;
>> outWinCfgADC.dataAccessType = VME_DATA;
>> outWinCfgADC.windowSizeL = 0x10000;
>> outWinCfgADC.xferProtocol = VME_SCT;
>> outWinCfgADC.addrSpace = VME_A16;
>> outWinCfgADC.maxDataWidth = VME_D16;
>> outWinCfgADC.xlatedAddrL = 0x10000000;
>>
>> I think that 0x10000 for window size is big enough to encompass the
>> whole A16 addressable space. With the 0x10000000 xlatedAddr I get no
>> errors and read the desired registers when I increment this address
>> to 0x1000A000. But nevertheless it seems strange to me that the
>> device does not accept xlatedAddr lower that 0x10000. Maybe its due
>> to the configuration of the VME controller?
>>
>
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