RoB-in Self Test
The ROB-IN selftest will enable data to be inserted into the
ROB at the input stage to allow the ROB-IN and buffer manager to be
tested. To test the hardware function the data must have the beginning
and end marked with a control word and must be able to be set to
produce events of any length up to about 5 pages. With pages of 256
long words, to enable events greater than 4 pages would require 11
bits. Thus there should be an 11 bit register which can be set to the
required event length, and an 11 bit counter to count to the end of
the event. Each event must also have an event ID at a fixed position
in the data -- this can be generated as the first data after the
beginning of event mark. At least 1024 event IDs must be generated so
that the whole indexing table of the buffer manager is used; this will
require a 10 bit counter. The rest of the event data is not important;
it could be a repeat of the event ID or it could be a test pattern
like 3c6. The maximum data rate of this test data source will be 134
MB/s. To stop this overrunning, the counter must be stopped by the
xoff signal.
This test feature requires 32 registers and hasn't yet been
added to the logic in the PLD. The currently used PLD has the largest
capacity in the range, so if the test logic exceeds the available
logic space the feature will be left out until a device with more
space becomes available.
BJG /
b.green@rhbnc.ac.uk