Oh... sorry for the noise, I did a mistake about minix paritions and wasn't
reading the correct bytes. I also noticed extra bytes as the end of
512-bytes, I guess this is about CRC check according to comments. Anyway, I
understand SD-card uses internal 512-bytes, not related to some higher level
of sectors (filesystem's).

Right ?

Cheers,
Seb

2011/4/20 Sebastien Lelong <[email protected]>

> OK, I can see many things about sectors of 512 bytes, this doesn't fit my
> need at all, as I need 1024 bytes / sectors. I'd say sd_card library
> shouldn't have anything related to sectors or the like, as it is something
> related to file systems, and you may just use your SD-Card without
> considering any of these.
>
> But since I'm no SD expert, there could be a reason to do so. Still,
> setting address with sd_start_read(sector) ends with accessing SD-card on a
> byte-level, not sector.
>
> Cheers,
>  Seb
>
>
> 2011/4/20 Sebastien Lelong <[email protected]>
>
>> Hi Matt,
>>
>> Some more feedback about current sd_card.jal library:
>>
>>   - send_command() should be prefixed with sd_send_command() to avoid
>> potential collision
>>   - I wanted to use sd_data_byte, to read card byte by byte, but it seems
>> already "infected" by some filesystems stuff: it increment a counter related
>> to sector, dealing with 512 bytes.
>>   - in the same procedure, there seems to be special values when reading
>> SPI (eg. 0xFE). What if I need to read these values ? I don't understand the
>> following loop:
>>
>>    if sd_byte_count == 0 then               -- beginning of sector read
>>       while spi_master != 0xFE loop      -- wait till data is ready to
>> read
>>       end loop
>>    end if
>>
>> Basically this is why my sample doesn't work, commenting the "while" loop
>> fixes the issue.
>>
>> Shouldn't I use this procedure ? Shouldn't it be completely independent
>> from filesystem concerns ?
>>
>> Thanks for your light !
>>
>> Cheers,
>> Seb
>>
>>
>>
>> 2011/4/19 mattschinkel <[email protected]>
>>
>>> Sure, and also check if pragma inline is a good idea.
>>>
>>> Matt.
>>>
>>> On Apr 19, 12:33 pm, Sebastien Lelong <[email protected]>
>>> wrote:
>>> > 2011/4/19 mattschinkel <[email protected]>
>>> >
>>> > > I prefer to take the spi init procedure and split it into two.
>>> >
>>> > OK, do you want me to take care of this ?
>>> >
>>> > Cheers,
>>> > Seb
>>> >
>>> >
>>> >
>>> > > spi_master_hw_set_mode(byte in mode)
>>> > > spi_master_hw_set_speed(byte in speed)
>>> >
>>> > > The set speed procedure may not be used as often, however there are
>>> > > some devices that require SPI commands to be slower then SPI data
>>> > > transfers. For example, mp3 decoder vs1053b
>>> >
>>> > > Then add another alias to the sample
>>> >
>>> > > alias spi_master_set_mode is spi_master_hw_set_mode
>>> >
>>> > > Matt.
>>> >
>>> > > On Apr 19, 6:42 am, Sebastien Lelong <[email protected]>
>>> > > wrote:
>>> > > > OK, thanks for pointing this. How can we solve this in order
>>> sd_card.jal
>>> > > to
>>> > > > be fully generic ? I remember we have the exact same problem with
>>> > > ethernet
>>> > > > libs.
>>> >
>>> > > > Cheers,
>>> > > > Seb
>>> >
>>> > > > 2011/4/19 mattschinkel <[email protected]>
>>> >
>>> > > > > Thanks.
>>> >
>>> > > > > You may also want to pay attention to these lines (if you are
>>> using
>>> > > > > more then one SPI device that use different modes)
>>> >
>>> > > > >   -- put spi into mode 11
>>> > > > >   if SD_ALWAYS_SET_SPI_MODE == TRUE then
>>> > > > >      SSPCON_CKP = 1
>>> > > > >      SSPSTAT_CKE = 0
>>> > > > >   end if
>>> >
>>> > > > > All of my SPI libs use these lines so the devices can be used
>>> > > > > together.
>>> >
>>> > > > > SD_ALWAYS_SET_SPI_MODE is defined in the sample.
>>> >
>>> > > > > Matt.
>>> >
>>> > > > > --
>>> > > > > You received this message because you are subscribed to the
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>>> >
>>> > > > --
>>> > > > Sébastien Lelonghttp://www.sirloon.nethttp://sirbot.org
>>> >
>>> >
>>>
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>>>
>>
>>
>> --
>> Sébastien Lelong
>> http://www.sirloon.net
>> http://sirbot.org
>>
>
>
>
> --
> Sébastien Lelong
> http://www.sirloon.net
> http://sirbot.org
>



-- 
Sébastien Lelong
http://www.sirloon.net
http://sirbot.org

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