Artesyn MVME5100, Programmer'S Reference Manual, Page: 135 / 318

Hawk PCI Host Bridge & Multi-Processor Interrupt Controller
MVME5100 Single Board Computer Programmer’s Reference (6806800H17B)
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The encoding of this field is shown in the following table:
SPRQ
Speculative PCI Request. If set, the PHB PCI Master will perform speculative PCI requesting
when a PCI bound transaction has been retried due to bridge lock resolution. If cleared, the PCI
Master will only request the PCI bus when a transaction is pending within the PHB FIFOs.
WLRTx
Write Lock Resolution Threshold. This field is used by the PHB to determine a PPC bound write
FIFO threshold at which a bridge lock resolution will create a retry on a pending PCI bound
transaction.
The encoding of this field is shown in the following table.
Table 2-34 PPC/PCI Clock Ratio Field
XPR PPC60x/PCI clock ratio
000 Undefined
001 1:1
010 2:1
011 3:1
100 3:2
101 Undefined
110 5:2
111 Undefined
Table 2-35 Write Lock Resolution Threshold
WLRT Write lock resolution threshold
00 Match write threshold mode (i.e. PSATTx WXFT)
01 Immediate
10 FIFO full
11 FIFO full