5.2 PolarFire SoC and RT PolarFire SoC Reboot

The system controller plays an integral part in booting the MSS. When System Controller Suspend mode is enabled, the System Controller boots the MSS at power-up or device reset and then enters System Controller Suspend mode. During System Controller Suspend mode, the System Controller is in reset and is unable to support services as it normally supports, including MSS boot. If the MSS is running and determines it requires a reboot, it must force the System Controller to exit System Controller Suspend mode. To do this, it is required to instantiate the PFSOC_SCSM macro and connect the input to the MSS REBOOT_REQUESTED_M2F output as shown in the following figure. The MSS REBOOT_REQUESTED_M2F port is exposed by checking the ‘Expose Feedback ports to Fabric’ box in the MSS Configurator. Other connections to this port are not supported. With this connection added to the user’s FPGA fabric design, whenever the MSS REBOOT_REQUESTED_M2F output is asserted, the System Controller exits System Controller Suspend mode and processes the pending MSS reboot request. Once the MSS boots, the REBOOT_REQUESTED_M2F output de-asserts and the System Controller returns to Suspend mode. The System Controller status can be monitored through the SC_STATUS macro.