Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 18 Mar 2004 13:04:57 -0600

Kate Feng wrote:

Measured 60x bus bandwidth (MPC7450 + GT64260) :
    Pipelining  disabled : 177 MBytes/sec
    Pipelining  enabled :  589 MBytes/sec
Thus, theoretically, one should be able to disable  the
address pipelining  of the mvme5500 (MPC7455 + GT64260).

There's no way of getting 589MB/s through a regular VMEbus.
Address pipelining on the VMEbus (which was causing the problems with the
VME-MXI-1 modules) is not related to address pipelining by the CPU on its
local bus, which is presumably what the Motorola paper is quoting. The
VMEbus cycle timings are completely controlled by the Tundra Universe-2
chip on Motorola PowerPC boards, and VMEbus address pipelining cannot be
disabled.
- Andrew
--
Dear God, I didn't think orange went with purple until I saw
the sunset you made last night.  That was really cool. - Caro

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System