Re: Sandisk Compact Flash

Re: Sandisk Compact Flash

[David Hinds]

On Wed, Jul 13, 2005 at 07:04:38PM +0530, somshekar.c.kadam@in.abb.com wrote:
> 
> I ma newbie to compactflash driver , I am using mpc862 PPC processor
> on my custom board having 64mb ram running linuxppc-2.4.18 kernel .
> i am using Sandisk Extreme CF 1GB which is 133x high speed, but
> found the performance with other kingston 1GB CF with slower speed ,
> is both same , CF is implemented on pcmcia port , i am not sure what
> is the mode set for transfer , Feature set command is used in which
> it sets the PIO mode or Multiword DMA transfer mode by specifying
> its value in Sector count register , i am not able to understand in
> linux kernel ide driver where this is set , is it by default set ,
> this mode is set or we need to set it , i think we should assign
> this value , right now i am not able to trace this in my code.  ,

All Compact Flash cards, in 16-bit PCMCIA card readers, operate in PIO
mode 1 (polled IO, no DMA), which means you will get only about 1
MB/sec regardless of the card's claimed tranfer speed.  Some cameras
also only support this mode; others will run CF cars in "TrueIDE"
mode, which is required to use the DMA transfer modes.

There are high performance CF card readers that can use TrueIDE mode:
both CardBus ones and Firewire ones.  For example:

http://www.dpreview.com/news/0310/03102103delkincardbustest.asp

It sounds like your card reader is one of the slow 16-bit ones.

-- Dave

Re: Sandisk Compact Flash

[Michael Krufky]

David Hinds wrote:

>On Wed, Jul 13, 2005 at 07:04:38PM +0530, somshekar.c.kadam@in.abb.com wrote:
>  
>
>>I ma newbie to compactflash driver , I am using mpc862 PPC processor
>>on my custom board having 64mb ram running linuxppc-2.4.18 kernel .
>>i am using Sandisk Extreme CF 1GB which is 133x high speed, but
>>found the performance with other kingston 1GB CF with slower speed ,
>>is both same , CF is implemented on pcmcia port , i am not sure what
>>is the mode set for transfer , Feature set command is used in which
>>it sets the PIO mode or Multiword DMA transfer mode by specifying
>>its value in Sector count register , i am not able to understand in
>>linux kernel ide driver where this is set , is it by default set ,
>>this mode is set or we need to set it , i think we should assign
>>this value , right now i am not able to trace this in my code.  ,
>>    
>>
>It sounds like your card reader is one of the slow 16-bit ones.
>
I recommend picking up a CF-to-IDE adapter, such as this:

http://www.acscontrol.com/Index_ACS.asp?Page=/Pages/Products/CompactFlash/IDE_To_CF_Adapter.htm

...It works great for me!

There are a bunch of companies selling these... Google "cf ide adapter".

-- 
Michael Krufky

Re: Sandisk Compact Flash

[David Hinds]

On Sat, Jul 16, 2005 at 03:04:54AM -0400, Michael Krufky wrote:

> I recommend picking up a CF-to-IDE adapter, such as this:
> 
> http://www.acscontrol.com/Index_ACS.asp?Page=/Pages/Products/CompactFlash/IDE_To_CF_Adapter.htm

That's fine if you have a spare IDE port, but unlikely if you're
using a laptop.  Also these do not support hot swapping.

-- Dave

Re: Sandisk Compact Flash

[Norbert van Nobelen]

So then you will have to reboot sometimes. BTW, IDE can be hot swapped if you 
are carefull:
Umount the device,
unplug it.
Plug in the same device (same model)
Remount.
A bit risky to your hardware, but I have used this way for harddisks several 
time when a system has to keep running. Never used it for compact flash 
though.

Another option: Buy an USB card controller or a pcmcia controller for in your 
pc. Costs about $10,-

Op zaterdag 16 juli 2005 18:31, schreef u:
> On Sat, Jul 16, 2005 at 03:04:54AM -0400, Michael Krufky wrote:
> > I recommend picking up a CF-to-IDE adapter, such as this:
> >
> > http://www.acscontrol.com/Index_ACS.asp?Page=/Pages/Products/CompactFlash
> >/IDE_To_CF_Adapter.htm
>
> That's fine if you have a spare IDE port, but unlikely if you're
> using a laptop.  Also these do not support hot swapping.
>
> -- Dave
> -
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Re: Sandisk Compact Flash

[somshekar.c.kadam]

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Hi David ,

    On my controller CF INPACK pin is connected to 3.3v.  so Comapct flash
with DMA capabilty will not be supported , i understood this .
but i did not undesrtand why only PIO mode 1 is supported is it , why not
PIO mode 4 , is it a limitation of pcmcia driver , correct me if i am wrong

Thanks In Advance
Somshekar



                                                                                                     
 (Embedded     David Hinds <dhinds@sonic.net>                                                        
 image moved   07/15/2005 10:51 AM                                                                   
 to file:                                                                                            
 pic05705.pcx)                                                                                       
                                                                                                     
                                                                                                     



To:    somshekar.c.kadam@in.abb.com
cc:    linux-kernel@vger.kernel.org
Subject:    Re: Sandisk Compact Flash

Security Level:?              Internal

On Wed, Jul 13, 2005 at 07:04:38PM +0530, somshekar.c.kadam@in.abb.com
wrote:
>
> I ma newbie to compactflash driver , I am using mpc862 PPC processor
> on my custom board having 64mb ram running linuxppc-2.4.18 kernel .
> i am using Sandisk Extreme CF 1GB which is 133x high speed, but
> found the performance with other kingston 1GB CF with slower speed ,
> is both same , CF is implemented on pcmcia port , i am not sure what
> is the mode set for transfer , Feature set command is used in which
> it sets the PIO mode or Multiword DMA transfer mode by specifying
> its value in Sector count register , i am not able to understand in
> linux kernel ide driver where this is set , is it by default set ,
> this mode is set or we need to set it , i think we should assign
> this value , right now i am not able to trace this in my code.  ,

All Compact Flash cards, in 16-bit PCMCIA card readers, operate in PIO
mode 1 (polled IO, no DMA), which means you will get only about 1
MB/sec regardless of the card's claimed tranfer speed.  Some cameras
also only support this mode; others will run CF cars in "TrueIDE"
mode, which is required to use the DMA transfer modes.

There are high performance CF card readers that can use TrueIDE mode:
both CardBus ones and Firewire ones.  For example:

http://www.dpreview.com/news/0310/03102103delkincardbustest.asp

It sounds like your card reader is one of the slow 16-bit ones.

-- Dave





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Re: Sandisk Compact Flash

[David Hinds]

On Wed, Jul 20, 2005 at 12:49:00PM +0530, somshekar.c.kadam@in.abb.com wrote:
> 
> Hi David ,
> 
> On my controller CF INPACK pin is connected to 3.3v.  so Comapct
> flash with DMA capabilty will not be supported , i understood this .
> but i did not undesrtand why only PIO mode 1 is supported is it ,
> why not PIO mode 4 , is it a limitation of pcmcia driver , correct
> me if i am wrong

The 16-bit PCMCIA bus is maxed out at about 1 MB/sec; that's all the
bandwidth there is.  What your card supports is irrelevant.

I'm not sure whether the PCMCIA mode actually corresponds to any of
the official PIO modes 0, 1, etc.  It is just "slow".

-- Dave

Re: Sandisk Compact Flash

[somshekar.c.kadam]

[-- Attachment #1: Type: text/plain, Size: 2041 bytes --]





HI David ,

Thanks a Lot for clearing all the doubts , yes its the drawback of my
hardware which i cant use high speed compact flash as DMA is not supported
,

Is there anyway with the help of software to message that , this compact
flash cant be used anymore , first of all is this a good idea to have such
a functinality on embedded system of saying compact flash is going to die
please replace it , or just by the number of years of compact flash we say
replace the compact flash

Thanks In Advance
Somshekar


                                                                                                     
 (Embedded     David Hinds <dhinds@sonic.net>                                                        
 image moved   07/20/2005 09:56 PM                                                                   
 to file:                                                                                            
 pic18875.pcx)                                                                                       
                                                                                                     
                                                                                                     



To:    somshekar.c.kadam@in.abb.com
cc:    linux-kernel@vger.kernel.org
Subject:    Re: Sandisk Compact Flash

Security Level:?              Internal

On Wed, Jul 20, 2005 at 12:49:00PM +0530, somshekar.c.kadam@in.abb.com
wrote:
>
> Hi David ,
>
> On my controller CF INPACK pin is connected to 3.3v.  so Comapct
> flash with DMA capabilty will not be supported , i understood this .
> but i did not undesrtand why only PIO mode 1 is supported is it ,
> why not PIO mode 4 , is it a limitation of pcmcia driver , correct
> me if i am wrong

The 16-bit PCMCIA bus is maxed out at about 1 MB/sec; that's all the
bandwidth there is.  What your card supports is irrelevant.

I'm not sure whether the PCMCIA mode actually corresponds to any of
the official PIO modes 0, 1, etc.  It is just "slow".

-- Dave





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