Re: [PATCH v3] mtd/nand : workaround for Freescale FCM to support large-page Nand chip

On 09/01/2011 04:41 AM, LiuShuo wrote:

After doing some tests, I found that the elbc controller can read/write
4k with one command
if we insert a FIR_OP_NOP between first half reading/wring and second
half reading/writing.(delay for something ?)

From the docs:

A NOP instruction that appears in FIR ahead of the last instruction
is executed with the timing of a regular command instruction, but
neither LFCLE nor LFWE are asserted.  Thus a NOP instruction may be
used to insert a pause matching the time taken for a regular command
write.

So the NOP does generate a delay.  Would be nice to know exactly why
it's required.

Have you tried doing this under load with parallel NOR activity?  With
CE-don't-care operation, during the times when CE is not asserted, does
it matter what happens with CLE/ALE/RE?  These signals could be driven
for another chipselect during that time.

-Scott