Method for accessing scan chains and updating EEPROM-resident FPGA code through a system management processor and JTAG bus
View Patent ↗A method of updating programmable device configuration code stored in EEPROMs of a system is operable on complex systems having separate management and system processors. The method includes executing a sequence for updating programmable device configuration code on a management processor of the system including erasing the EEPROMs, writing at least one block of configuration code to the EEPROMs, and checking for errors after writing. The errors checked for include failure of a FIFO to empty. Upon detecting errors, the method includes automatically retrying writes. Embodiments of the method are operable on systems having multiple serial busses interconnecting EEPROMs to a common configuration logic, and on systems having multiple management processors each capable of accessing the common configuration logic.
1. A method of updating programmable device configuration code stored in EEPROMs of a system comprising the steps of:
providing at least one serial bus interconnecting EEPROMs of the system with a common configuration logic;
obtaining a file of configuration code;
verifying compatibility of the file with the serial bus;
erasing at least one EEPROM of the EEPROMs;
writing at least one block of configuration code to the EEPROMs; and
checking for errors after writing blocks, the errors including failure of a FIFO to empty, and retrying the step of writing at least one block upon an error.
2. The method of claim 1 , further comprising the step of soft-booting at least one programmable logic device to load configuration code from an EEPROM of the at least one EEPROMs into the programmable logic device.
3. The method of claim 2 , wherein the system has more than one processor, and further comprising the step of allocating the common configuration logic to prevent simultaneous access by more than one processor of the system.
4. The method of claim 2 , wherein the at least one serial bus interconnecting EEPROMs of the system with a common configuration logic is a plurality of serial busses, and further comprising the step of selecting a particular serial bus of the plurality of serial busses.
5. The method of claim 2 , wherein at least one programmable logic device is an FPGA, and wherein the method is executed automatically upon an error loading configuration code from EEPROM into the FPGA.
6. The method of claim 2 , wherein at least one programmable logic device is an FPGA, and wherein the method is executed automatically upon an error loading configuration code from EEPROM into the FPGA.
7. The method of claim 1 , wherein the at least one serial bus interconnecting EEPROMs of the system with a common configuration logic is a plurality of serial busses, and further comprising the step of selecting a particular serial bus of the plurality of serial busses.
8. A method of updating programmable device configuration code stored in EEPROMs of a system, the system having separate management and system processors, comprising executing a sequence for updating programmable device configuration code on a management processor of the system, the sequence for updating programmable device configuration code further comprising the steps of:
erasing the EEPROMs;
writing at least one block of configuration code to EEPRMs;
checking for errors after writing the at least one block, the errors including failure of a FIFO to empty, and retrying the step of writing at least one block upon error;
verifying that a file contains configuration code compatible with the system;
wherein the step of verifying that a file contains configuration code compatible with the system comprises polling a JTAG bus of the system to determine the configuration of the JTAG bus, and comparing the configuration with a configuration stored in the file.