[U-Boot] MPC85xx UPM NAND

[Jens Gehrlein]

Hi Alemao,

Alemao schrieb:
> Hi all,
> 
> I have used UPM in a MPC83xx with LBC running at 64MHz.
> 
> Now I have a MPC85xx, with LBC at 41MHz.
> 
> It only works if I put a delay in drivers/mtd/nand/fsl_upm.c :
> nand_write_buf(), otherwise I lost one byte. But it takes toooo long
> writing, which makes their use impractical.
> 
> I saw in board/tqc/tqm85xx/nand.c that the driver use an UPM
> configuration for each frequency.
> 
> Can some one tell me what signals I have to change or just some hint
> about what could be causing this behavior?
> 
> Im using UPM waveform editor and u-boot-2009-03.

The UPM tables and ORx settings for TQM85xx are optimized for each
LBC frequency, the used NAND chips and the used PCB.

To get the right timing for *your* HW you probably need a timing
simulation before. Eventually, you have to connect a timing analyzer
and check the bus signals after.

If the timing is correct, check the right order of bus commands,
too. The issue with the e500 core is, that it may reorder machine
instructions. Perhaps you need to instert "mbar" instructions.

Sorry, I'm not a HW guy, so I can't tell you more. I didn't do the
simulation and analysis myself.

Kind regards,
Jens