AR# 32028: 10.1EDK - How do I assign priorities to PLB masters in XPS GUI?
10.1EDK - How do I assign priorities to PLB masters in XPS GUI?
When we have multiple PLBv46 masters connected to the bus, is there a way in Xilinx Platform Studio (XPS) GUI to assign arbitration priority to individual master?
The Processor Local Bus (PLB) v46 has two arbitration schemes:
1. Fixed Priority.C_ARB_TYPE = 0. The bus arbitrates according to the fixed priority of the master. Master priority can be set using the following two solutions. 2. Round Robin.C_ARB_TYPE = 1. The last master to win arbitration and be granted the buswill be the lowest priority available master to be granted the bus in the next arbitration cycle.
The priority of the masters on a bus depends on the order in which the masters are connected in the Microprocessor Hardware Specification (MHS) file. So, if you put a higher priority master first in the MHS, then the bus will give it higher priority.
On the master bus interface connection in the MHS, you can specify a property called POSITION = <n> (starting with 1):
BUS_INTERFACE MPLB = plb, POSITION = 1
For more details, refer to the MHS chapter of the psf_rm.pdf manual.