System and method to initialize registers with an EEPROM stored boot sequence
View Patent ↗A system and method to initialize registers with an EEPROM stored boot sequence is described. The method includes reading configuration records from an EEPROM coupled to an ASIC upon system reset. The configuration records specify target configuration registers and data to be written to the registers. The configuration records are translated to register write requests and data is written to the target registers via a bus of the ASIC to initialize the registers. Other masters, such as a processor, may be blocked from accessing the registers during the initialization.
1. A method comprising:
reading configuration records from an electrically erasable programmable read-only memory (EEPROM) coupled to an application specific integrated circuit (ASIC) during an initialization phase upon system reset;
writing data to target registers from an EEPROM via a bus of the ASIC to initialize the registers during the initialization phase, wherein the data and target registers are specified in the configuration records; and
restricting a processor external to the ASIC to have read only access to the target registers during the initialization phase.
2. The method of claim 1 , wherein translating the records to register write requests comprises translating the records to register write requests at the EEPROM controller in the ASIC.
3. The method of claim 2 further comprising allowing the EEPROM controller to have write access to the target registers during the initialization phase.
4. The method of claim 3 , wherein allowing the EEPROM controller to have write access to a target register while allowing the processor to have read only access to the target register comprises including one or more values in the write requests originating from the EEPROM controller that allow a bus master to differentiate EEPROM write requests to the target register from write requests originating from the processor.
5. The method of claim 1 , further comprising blocking the processor from accessing the bus until the target registers have been initialized.
6. The method of claim 1 , wherein reading configuration records from the EEPROM comprises reading a record header including information about a command.
7. The method of claim 6 , wherein translating the records to write requests comprises translating the records to write requests if the command is a write command.
8. The method of claim 6 , wherein reading configuration records from the EEPROM comprises reading configuration records from the EEPROM sequentially while the command is a write command.
9. The method of claim 6 , wherein reading configuration records from the EEPROM comprises jumping to a specified address to read the next configuration record when the command is a jump command.
10. An apparatus comprising:
an application specific integrated circuit (ASIC) including a plurality of configuration registers; and
an electrically erasable programmable read-only memory (EEPROM) coupled to the ASIC to initialize the configuration registers of the ASIC upon system reset via stored configuration records, the ASIC to allow read only access to external devices during initialization of the configuration registers.
11. The apparatus of claim 10 , wherein the ASIC further comprises an EEPROM controller coupled to the EEPROM to read the configuration records of the EEPROM upon system reset.
12. The apparatus of claim 10 , wherein the ASIC further comprises a bus controller coupled to an EEPROM controller to control activity on a bus and wherein the registers are initialized via the bus.
13. The apparatus of claim 10 , wherein the configuration records include addresses of the registers to be initialized and data to be written to the registers during initialization.
14. An article of manufacture comprising:
a machine accessible medium including content that when accessed by a machine causes the machine to:
read configuration records from an electrically erasable programmable read-only memory (EEPROM) coupled to an application specific integrated circuit (ASIC) during initialization upon system reset;
allow a processor external to the ASIC to have read only access to a target register during the initialization;
write data to target registers by an EEPROM controller via a bus of the ASIC to initialize the registers during the initialization, wherein the data and target registers are specified in the configuration records.
15. The article of manufacture of claim 14 , wherein the machine-accessible medium further includes content that causes the machine to block the processor from accessing the bus until the target registers have been initialized.
16. The article of manufacture of claim 14 , wherein the machine accessible medium including content that when accessed by the machine causes the machine to read configuration records from the EEPROM comprises the machine accessible medium including content that when accessed by the machine causes the machine to read a record header including information about a command.
17. The article of manufacture of claim 16 , wherein the machine accessible medium including content that when accessed by the machine causes the machine to translate the records to write requests comprises the machine accessible medium including content that when accessed by the machine causes the machine to translate the records to write requests if the command is a write command.
18. The article of manufacture of claim 16 , wherein the machine accessible medium including content that when accessed by the machine causes the machine to read configuration records from the EEPROM comprises the machine accessible medium including content that when accessed by the machine causes the machine to read configuration records from the EEPROM sequentially while the command is a write command.
19. The article of manufacture of claim 16 , wherein the machine accessible medium including content that when accessed by the machine causes the machine to read configuration records from the EEPROM comprises the machine accessible medium including content that when accessed by the machine causes the machine to jump to a specified address to read the next configuration record when the command is a jump command.
20. A system comprising:
a processor;
an electrically erasable programmable read-only memory (EEPROM) to initialize configuration registers during initialization upon system reset via stored configuration records comprising a record header;
a dynamic random access memory (DRAM); and
an application specific integrated circuit (ASIC) coupled to the EEPROM, the processor and to the DRAM, the ASIC including:
a plurality of configuration registers to be initialized upon system reset;
an EEPROM controller coupled to the EEPROM to read the configuration records from the EEPROM and translate the records to register write requests; and
a bus controller to control access to the configuration registers, the processor having read only access to the configuration registers during the initialization and the EEPROM controller having read and write access during the initialization.