User`s guide

DWMBB Adapter
3.6.1 No Assertion and No Response to XMI Lockout Mode
The Mode 0 No Assertion and No Response to XMI Lockout Mode causes
the DWMBB to ignore the XMI LOCKOUT L signal. The DWMBB does
not assert XMI LOCKOUT L when it receives LOC responses to IREAD
transactions. It does not respond to the assertion of XMI LOCKOUT L by
another XMI node and continues to issue all requests it receives from the
VAXBI, including IREADs.
3.6.2 Respond to XMI Lockout Mode
The Mode 1 Respond to XMI Lockout Mode causes the DWMBB to respond
to the assertion of the XMI LOCKOUT L signal from another XMI node
but does not allow the DWMBB to assert the signal.
XMI LOCKOUT L Response
If the DWMBB has an IREAD pending when another node asserts XMI
LOCKOUT L, it can issue, at most, one IREAD transaction after it sees
the assertion of XMI LOCKOUT L. No further IREADS are issued until
XMI LOCKOUT L deasserts.
If XMI LOCKOUT L is asserted by another node while the DWMBB
has an IREAD pending, and if the DWMBB has not passed the point in
its DMA transaction where it checks XMI LOCKOUT L, the DWMBB
prevents the pending IREAD from getting issued on the XMI. Instead, the
DWMBB terminates the IREAD by returning a LOC (RETRY) response
back to the VAXBI.
If XMI LOCKOUT L is asserted by another node while the DWMBB has
an IREAD pending, and if the DWMBB has passed the point in its DMA
transaction process where it checks XMI LOCKOUT L, the DWMBB issues
the pending IREAD on the XMI.
3.6.3 Assert XMI Lockout Mode
The Mode 2 Assert XMI Lockout Mode is the DWMBA compatibility mode
for the DWMBB.
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 in the Lockout Limit field, AUTLR<31:28>, which is
set by software.
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.
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