On Mon, Oct 12, 2009 at 4:24 AM, Jens Gehrlein sew_s@tqs.de wrote:
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.
I tried to use the same frequency that I was using in my MPC83xx board, I got the same problem.
Can PCB layout significantly influence at 66Mhz? Or 41MHz?
Cause I had programmed UPM with the same array in both processors.
What do you mean by "instert mbar instructions"? Where?
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
Thanks,
-- Alemao