Circuit serial programming of default configuration

• US 6,606,670 B1
• Filed: 08/16/2000
• Issued: 08/12/2003
• Est. Priority Date: 08/16/2000
• Status: Active Grant

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Microchip Technology Incorporated
• Inventors: Negley, Bruce, Filicetti, Craig, Stoneking, Rick
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Mai, Rijue
• Application Number:
  US09/639,840
• Time in Patent Office: 1,091 Days
• Field of Search: 710/8, 710/11, 710/14, 710/31, 710/33, 710/129, 710/131, 710/200, 712/225, 712/245, 712/223, 713/400, 713/600
• US Class Current: 710/14
• CPC Class Codes: G06F 8/654 using techniques specially adapted for alterable solid state memories, e.g. for EEPROM or flash memories

Abstract

According to the present invention, a device and method accomplish in-line serial programming of a default configuration into a configurable device for connection to a message-based network. The configurable device includes an input/output unit, an electrically programmable read only memory (EPROM), programming logic and a protocol engine for exchanging messages with a message-based bus based on the default configuration. The input/output unit includes pins and logic for configuring a portion of the pins to operate in both a normal mode and as a clock pin, a data pin and a program pin in a programming mode. The electrically programmable read only memory (EPROM) stores a default configuration for the configurable device. The programming logic is coupled to the input/output unit. It receives signals from the data, clock and program pins and determines data and commands based on the signals. The programming logic also executes the commands to program the data, which comprises the default configuration, into the EPROM.

Claims

1. A configurable device for message-based network communication, comprising:

an input/output unit including pins for connecting the configurable device to a system, the input/output unit further including logic for configuring a portion of the pins to operate in both a normal mode and as a clock pin, a data pin and a program pin in a programming mode;

an electrically programmable read only memory (EPROM) for storing a default configuration for the configurable device;

programming logic, coupled to the input/output unit, the programming logic determining data and commands based on the signals from the data, clock and program pins and executing the commands to program the data into the EPROM, the data comprising the default configuration; and

a protocol engine for exchanging messages with a message-based bus based on the default configuration.

2. The configurable device according to claim 1, wherein the program pin is switchably isolated from other devices in the system by a resistor.

3. The configurable device according to claim 1, wherein the data, clock and program pins are switchably isolated from other devices in the system by a resistor.

4. The configurable device according to claim 1, wherein the programming logic further comprises a shift register coupled to the clock and data signal for serially clocking in the data.

5. The configurable device according to claim 4, wherein the programming logic further comprises a command register coupled to the clock and data signal for serially clocking in at least one of the commands.

6. The configurable device according to claim 1, wherein the program pin receives a programming voltage that is greater in amplitude than the voltage level of a power signal applied to the configurable device to initiate a programming mode.

7. The configurable device according to claim 1, further comprising:

a volatile memory for storing the default configuration as an alterable configuration upon application of power to the device in a normal operating mode.

8. The configurable device according to claim 7, further comprising:

a transfer unit for transferring the default configuration from the EPROM to the volatile memory as the alterable configuration upon application of power.

9. The configurable device according to claim 8, further comprising:

a power on reset detector coupled to a power source for detecting a power on event and issuing a signal to the transfer unit indicating the application of power.

10. The configurable device according to claim 7, further comprising:

configuration registers within the volatile memory for storing at least a portion of the alterable configuration; and

modules coupled to the volatile memory, at least one of modules being configured for operation based on at least a portion of the alterable configuration stored in at least one of the configuration registers.

11. The configurable device according to claim 10, wherein the modules include the input/output unit and the protocol engine.

12. The configurable device according to claim 10, wherein the modules include an analog to digital converter.

13. The configurable device according to claim 10, wherein the protocol engine is a controller area network protocol engine.

14. A method of configuring a device for message-based network communication, comprising:

providing pins for connecting the configurable device to a system, a portion of the pins operating in both a normal mode and as a clock pin, a data pin and a program pin in a programming mode;

receiving clock, data and programming signals from the clock data and programming pins;

determining data and programming commands based on the data, clock and programming signals; and

executing the commands to program the data into an EPROM, the data comprising the default configuration;

wherein the configurable device further comprises a protocol engine for exchanging messages with a message-based bus based on the default configuration.

15. The method according to claim 14, wherein the program pin is switchably isolated from other devices in the system by a resistor.

16. The method according to claim 14, wherein the data, clock and program pins are switchably isolated from other devices in the system by a resistor.

17. The method according to claim 14, wherein the program programming signal initiates the programming mode and comprises a programming voltage that is greater in amplitude than the voltage level of a power signal applied to the configurable device.

18. The method according to claim 14, further comprising:

storing the default configuration as an alterable configuration in a volatile memory upon application of power to the device in a normal operating mode.

19. The method according to claim 18, wherein configuration registers within the volatile memory store at least a portion of the alterable configuration and wherein the configurable device further comprises modules coupled to the volatile memory, at least one of modules being configured for operation based on at least a portion of the alterable configuration stored in at least one of the configuration registers.

20. The method according to claim 19, wherein the modules include the input/output unit and the protocol engine.

21. The method according to claim 19, wherein the modules include an analog to digital converter.

22. The method according to claim 14, wherein the protocol engine is a controller area network protocol engine.