GR712RC-UM, Jun 2017, Version 2.9 157 www.cobham.com/gaisler
GR712RC
The BRM frequency of 12 MHz allows much less time for the access to complete than the other con-
figurations, and for this reason this frequency is not been listed as supported.
The B1553BRM and GRETH cores have elevated priority in the GR712RC arbiter over all other
AMBA masters, meaning that for latency calculation the B1553BRM will only have to wait for the
currently active master to complete its access before getting access to the AMBA bus. For the other
AMBA masters a round-robin arbitration scheme is used. The B1553BRM and GRETH cores are
never active at the same time since they conflict in the I/O matrix.
Note 1: This specific case is not supported.
Note 2: This specific case has not been validated.
TABLE 161. System versus BRM clock frequencies and latency times
System clock BRM clock Max arbitration latency Max access time
(MHz) (MHz) (system periods) (ns) (system periods) (ns)
24
1)
12 91 3792 6 250
32
2)
16 123 3844 14 251
40 20 165 4125 20 500
48 24 231 4812 22 458
64 16 249 3891 30 469
80 20 333 4162 42 525
96 24 333 4844 46 525
120 20 501 4175 64 533
144 24 699 4175 70 533
To Next Page
Loading...
Need help?
General
