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 <[email protected]> image moved 07/15/2005 10:51 AM to file: pic05705.pcx) To: [email protected] cc: [email protected] Subject: Re: Sandisk Compact Flash Security Level:? Internal On Wed, Jul 13, 2005 at 07:04:38PM +0530, [email protected] 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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