I2c ucode patch

[laurent.mohin at acterna.com]

Igor,

The need of ucode patch is due to the parameter ram organization into the dual
port ram (as described in table 16.3 of the MPC823e reference manual).
Below the table, you can read a little note saying that the SCC2 section will
overlap the SPI section if SCC2 is used for Ethernet and that SCC3 section will
overlap SMC1 section if SCC3 is used for Ethernet.
In your case, you don't need a ucode patch to make I2C working.

Laurent




IGOR LURI <iluri at fagorautomation.es> on 08/05/2002 14:12:03

To:   EMBEDDED LINUXPPC (Correo electrónico)
      <linuxppc-embedded at lists.linuxppc.org>
cc:
Subject:  I2c ucode patch


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Hi all,

We have a custom board based on a mpc 823e (revision B2) with  I2c ,
ethernet (on SCC 3), LCD etc..

Motorola says that concurrent operation of Ethernet and I2C or SPI is not
posible without a ucode patch, but:

- If we don't use I2c ucode patch, we can execute our aplication via nfs,
that reads voltages and temperatures via I2c, so ethernet and I2c work
concurrently.

-    If we use I2c ucode patch, aplication  fails while it tries to write
on I2c device.

Also, we have compared I2c ucode patch downloaded from Motorola and I2c
ucode patch of Denx Linux 2.4.4 kernel source and it seems to be different.

Our cuestion are:

Do we need I2c ucode relocation patch if our aplication works without it?
Why are different Motola and Linux ucode patches?

Thanks in advance.