CPU Interface Functional Overview
Specific CPUs Aspects
Copyright © 2002 Marvell
CONFIDENTIAL
Doc. No. MV-S300165-00, Rev. A
May 21, 2002, Preliminary
Document Classification: Proprietary Information
Page 23
Figure 4: PPC750FX CPU Keeper
Since the 'keepers' are not biased to drive the IOs one way or the other, any control signals that must be in a par-
ticular state leaving HRESET* have to be either driven to that state or pulled there by external resistors.
The designer can connect two 'keepers' on the same signals (i.e. multiple PPC750FX systems), since they will
always drive the same value. Theoretically, two keepers can end up in contention during power up. However, since
this would be unstable, any noise event would knock it to a '1' or '0'.
A
B
Chip pad