The recommended reset scheme uses the LinkUp signal from the PCIe bridge as an auxiliary reset to the proc_sys_reset core.
(i.e., PORT Aux_Reset_In = linkup). With this configuration, a system reset will cause the PCIe core to reset, which brings the link down and the PCIe link must retrain before the core asserts LinkUp to allow the processor system come out of reset.
In default XMD configuration, XMD will assert a reset before downloading an elf-file with the download command. XMD waits a normally reasonable time after the reset before starting the elf-file download; however, this time is not long enough for the pcie link to retrain, so the processor remains in reset when XMD tries to start the elf-file download.
Hence, it is necessary to configure XMD not to assert reset before downloading an elf-file. As noted in the bridge Product Specification, this can be accomplished with the option "reset_on_run system disable". However, the XMD EDK 10.1.3 does not properly download an elf-file when the reset_on_run is disabled in the systems using the PPC processor block.
The work-around for PPC-based V5 FX systems is not to connect LinkUp to the auxreset port of the proc_sys_reset module when xmd Is needed to download elf-files during development phase.
When xmd is not used, LinkUp should be connected to the proc_sys_reset port.
This is a short term workaround. The new core plbv46_pcie v4.00.a will have a more elegant reset scheme that is expected to work in the default xmd configuration.
The new core will be available in the EDK 11.1.