Okay, I'm using the ISP1362.v from the wiki. In SoPC builder, I get the following warnings which lead to errors when I try to generate the system.
Warning: ISP1362.avalon_slave_0: Signal "OTG_DATA" has unknown type "export".
Warning: ISP1362.avalon_slave_0: Signal readdata appears 2 times (only once is allowed)
Warning: ISP1362.avalon_slave_0: Signal readdatavalid_n appears 10 times (only once is allowed)
Warning: ISP1362.avalon_slave_0: Signal beginbursttransfer_n appears 2 times (only once is allowed)
Warning: ISP1362.avalon_slave_0: readdata[2] and writedata[16] must have the same width
Warning: ISP1362.avalon_slave_0: Slave with beginbursttransfer also needs burstcount for burst transfers
Warning: ISP1362.avalon_slave_0: Should have waitrequest signal for read burst transfers