DDC BU-65570T, Руководство по оборудованию

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H A R D W A R E O P E R A T I O N
Data Device Corporation 30 BU-65572T Manual
of „last‟ is reached, at which point the current table number will rollover to
the value of first. The incrementing of the current data table is
accomplished through the use of an intermessage routine.
7.5 Monitor Mode
The BU-65572T contains an independent message monitor for each bus
with the ability to filter messages in real time. Monitor selection or filtering
is performed through the use of a lookup table based on the RT address,
T/R, and sub-address of command words. Monitored messages are
stored in the shared RAM on the
BU-65572T , which allocates 12K words
for the monitor stack. Each entry in the monitor stack contains a header
followed by a variable number of data words. Contained with the
message header are the receive/transmit command(s), receive/transmit
status, message format, Bus (A or B), a capture flag, word count (actual
number of words in the message), a detected error field, and a 32-bit
time tag (1 µsec resolution).
The transfer of the messages from the c
ard‟s circular buffer to the host
memory/disk is determined by the capture flag, which is set upon
detection of a predefined event as specified by the „ddcCaptureEvent‟
command. Capture events include immediate, command template
match, exception, or trigger. The command template event is based on a
16-bit command word with a 16-bit mask. Exception events may be
programmed for any exception: invalid command, invalid data, invalid
status, gap preceding data, response time error, wrong RT address
error, status set condition or an illegal command. The trigger event uses
one of the two monitor input pins on the 40-pin D-type connector as a
trigger input.
The BU-65572T supports DMA transfers using its PCI Bus Mastering
Mode. The Monitor mode can autonomously transfer monitored data to
host buffer without host CPU intervention. This greatly improves the
efficiency of both the host and the
BU-65572T .
7.6 Interrupts
For each of the installed channels, both the BC/RT and the Monitor may
generate interrupts on a common output to the CompactPCI backplane
(#INTA). The hardware interrupt vector used by the
BU-65572T is
selected by the Plug-and-Play capability of the CompactPCI backplane
and BIOS. An important aspect of PCI interrupts is that they are
sharable. This means that the
BU-65572T can share an interrupt for all
buses on the card and all BU-65572T cards in the computer.
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