New MPC5200 Eratta/ATA Bugs
Eric N. Johnson (ACD)
ejohnson at acdstar.com
Tue Apr 26 05:22:56 EST 2005
Freescale just realeased a new version of the eratta (hardware bugs)
document for the MPC5200. It was posted last week, and adds some pretty
significant problems to the FEC Ethernet and IDE/ATA sections.
Specifically, I'm wonder if Eratta ID 485 may be the cause of some of the
IDE issues we've been attributing to Bestcomm:
"During the concurrent access of ATA DMA READ and PCI or LPC the
ATA_ISOLATION signal can be incorrectly driven when ATA is paused."
Unfortunately, their proposed workaround isn't appropriate for many
cases. They suggest that you not use "ATA_ISOLATION" and connect the ATA
device directly to the LP bus without any buffering. This could lead to
serious bus integrity issues, especially if the ATA device is connected by
a ribbon cable.
Eric Johnson, Electrical Engineer
Advanced Communication Design
7901 12th Avenue South
Bloomington, MN 55425
Ph: 952-854-4000 Fax: 952-854-5774
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