Re: 32 bit PCI, Byte Lanes

["Richard Iachetta" <iachetta@us.ibm.com>]

Your PCI interface to config space will have to be 32-bit because the OS
and BIOS will talk to that area.  I think that if you write or control the
device drivers that talk to your card, you can make sure all access to your
card are 16-bit, however I think the best solution is to support all 32-bit
(at least single beat) transactions and unpack/steer the data in your
device as you say.

Rich Iachetta
IBM Microelectronics Division -- Austin
World Wide Field Design Center
Phone: 512-838-6305   Tie Line: 678-6305


"Xavi Neuri" <xcano@neuricam.com> on 06/06/2001 05:14:19 AM

To:   <pci-sig@znyx.com>
cc:
Subject:  32 bit PCI, Byte Lanes



Hello,
I am working on a 32 bit PCI target . The fact is that the device works
with
16 data bits and I have no
idea which device (HOST/Bridge) impose the number of enable bytes in any
transfer. To fit
the bandwith it would be better use 32 bits data transfers and then, unpack
the Dword inside the device
in two words, but I don't know who is responsible or if is possible to
force
the transfer to work with 32 or 16
bits or is the bridge at his own who manage it.

Thank you

Xavier Cano