Internal Address multiplexing for MCP852

Meriin Michael-BMM063 Meriin at motorola.com
Sun May 30 17:42:36 EST 2004


I hope you are using U-boot as a bootloader.
So just try this SDRAM init (see attachment).
Good luck!

Best Regards,
     Michael Meriin

-----Original Message-----
From: Estevam Fabio-R49496
Sent: Friday, May 28, 2004 21:06
Subject: Internal Address multiplexing for MCP852

I am using Embedded Planet's EP852T board and there are 2 MT48LC4M16
SDRAMs in this board .

The .../ppcboot/u-boot-1.0.0x/board/ep852/ep852.c file has the 852 UPM
initialization routine and it is configured not to use the address
multiplexing capability of the 852. It uses an external address
multiplexer chip instead.

I would like to remove the external multiplexer chip and connect the 852
address lines directly to the SDRAMs without using a multiplexer.

I know that I will have to set the SAM bit in the SDRAM_OR1VALUE
register and also the AMX bits in the UPM RAM words of the const uint
sdram table[] array.

Please let me know if someone has already done that setting and would
like to share it with me.
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