User`s guide

DWMBB Adapter
• It "times out" with the timeout value that software set in the Lockout
Deassertion field, AUTLR<27:24>. The default is 2 to 3 ms.
• The DWMBB is reset.
While operating in Mode 2 (DWMBA compatibility mode), the DWMBB
does not respond to the assertion of the XMI LOCKOUT L signal by
another XMI node and continues to issue all requests it receives from the
VAXBI, including IREAD transactions.
3.6.4 Full XMI Lockout Mode
The Mode 3 Full XMI Lockout Mode is the default mode for the DWMBB
at power-up and XMI node reset.
XMI LOCKOUT L Assertion
The DWMBB asserts the XMI LOCKOUT L signal when the number
of consecutive Interlock Read (IREAD) attempts on the VAXBI equals
or exceeds the number software sets in the Lockout Limit field,
AUTLR<31:28>.
XMI LOCKOUT L is held asserted by the DWMBB until:
• It receives a GRD (Good Read Data), a CRD (Corrected Read Data), or
an RER (Read Error Response) to an IREAD transaction.
• It "times out" with the timeout value that software set in the Lockout
Deassertion field, AUTLR<27:24>. The default is 2 to 3 ms.
• The DWMBB is reset.
XMI LOCKOUT L Response
If the DWMBB/B module has an IREAD pending when another node
asserts XMI LOCKOUT L, it can issue (at most) the one pending IREAD
transaction on the XMI after it detects the assertion of XMI LOCKOUT
L. Further IREADs are not issued on the XMI until XMI LOCKOUT L
is deasserted. The DWMBB/B module returns a LOC response (RETRY)
back to the VAXBI when it cannot issue an IREAD on the XMI.
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