Hi Robert,
I tested a long-TREQ and
multi-TACK situation for GTRC-7 FPGA with a command sequence illustrated below.
I sent three TACK signals
during one TREQ high with a duration of 10,000 clock cycles (500 us) and a TACK
signal at the TREQ falling edge.
#CLK 0
1000
10,000
TREQ
__-----------------------------------------------_______
TACK
____-___________-_______-________________________-______
1st
2nd 3rd 4th
TOKEN______-_______________________-______-_____________-____
1st
2nd 3rd 4th
I received data like
following.
1st data: correct hit-strip
data with TOT=1000
2nd data: correct hit-strip
data with TOT=2044 (0x11111111100)
3rd data: correct hit-strip
data with TOT=2044
4th data: correct hit-strip
data with TOT=0
The TOT value of 2044 looks
something like error code. The response
time for every TOKEN signal was less than 1000 clock cycle. That should be correct behavior. I also tried all possible patterns of
event-tag number and checked that the response does not depend on the event-tag
number.
Please ask me if you have
any questions,
Mutsumi