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> Since you have to support SD card anyway, why not just use a second SD
card > instead of the NAND? He probably wants to support SSFDC given the description of the rest of his project. -- -- Lewin A.R.W. Edwards (http://www.zws.com/) Learn how to develop high-end embedded systems on a tight budget! http://www.amazon.com/exec/obidos/ASIN/0750676094/zws-20 |
Anybody implement NAND flash driver on LPC210x ?
Started by ●April 1, 2004
Reply by ●April 3, 20042004-04-03
Reply by ●April 6, 20042004-04-06
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--- In , Robert Adsett <subscriptions@a...> wrote: > The obvious reason for doing this is to avoid conflicts from multiple > process (or interrupts). Other wise you have to maintain shadow copies of > the outputs and (in an interrupt protected piece of code) update the shadow > and then the output. In psuedo code something like: > > disable_interrupts() > shadow_output = shadow_output & ~PERIPH_MASK -- zero area to be updated > shadow_output = shadow_output | (new_value & PERIPH_MASK) -- update > with new value > actual_output = shadow_output; > enable_interrupts() > > Some other micros provide similar facilities. The ST10 uses a construct > where a single register affects the I/O bit but maps two bit in the > register to each output, one bit patter set the output, a second clears the > output and the other two cause no effect. It's also used on internal > registers to avoid race conditions on bits that may be affected by both the > peripheral HW and SW. > > Finally note the writeup on the IOPIN register in the user manual "Note: > for test purposes, writing to this register stores the value in the output > register, bypassing the need to use both the IOSET > and IOCLR registers. This feature is of little or no use in an application > because it is not possible to write to individual bytes in > this register." > Robert > Thanks, Robert ! You dispel my doubts. |
Reply by ●April 7, 20042004-04-07
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--- In , Charles Manning <manningc2@a...> wrote: > > Since you have to support SD card anyway, why not just use a second SD card > instead of the NAND? > > -- Charles Charles, Your explanation benefits me as well. Thanks !! Considering the cost and size, we perfer to use NAND flash as built-in memory. SD card is for external large storage use. |
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Reply by ●April 7, 20042004-04-07
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--- In , "berrycake33" <berrycake33@y...> wrote: > --- In , Charles Manning <manningc2@a...> > wrote: > > > > Since you have to support SD card anyway, why not just use a second > SD card > > instead of the NAND? > > > > -- Charles > > Charles, > > Your explanation benefits me as well. > Thanks !! > > Considering the cost and size, > we perfer to use NAND flash as built-in memory. > SD card is for external large storage use. What capacity and speed exactly do you need? Try serial flash (SPI) from ST like M25P40-4Mbit/25MHz/SO8 or bigger (And you can have a number of devices on SPI bus) |
Reply by ●April 7, 20042004-04-07
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--- In , "berrycake33" <berrycake33@y...> wrote: > --- In , Charles Manning <manningc2@a...> > wrote: > > > > Since you have to support SD card anyway, why not just use a second > SD card > > instead of the NAND? > > > > -- Charles > > Charles, > > Your explanation benefits me as well. > Thanks !! > > Considering the cost and size, > we perfer to use NAND flash as built-in memory. > SD card is for external large storage use. if you insist to use NAND see http://www.xilinx.com/bvdocs/appnotes/xapp354.pdf Much easier would be to use SPI interface and for example serial flash like M25P40 from ST (4Mbit/25MHz/8SO) There is nothing wrong in using SD card for internal storage either. |
