Plug and play I2C slave

• US 6,363,437 B1
• Filed: 01/07/1999
• Issued: 03/26/2002
• Est. Priority Date: 01/07/1999
• Status: Expired due to Term

• Current Assignee: Optis Wireless Technology, LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sassi, Jari, Ptasinski, Kristoffer
• Primary Examiner(s): Shin, Christopher B.
• Application Number:
  US09/226,166
• Time in Patent Office: 1,174 Days
• Field of Search: 710/1-4, 710/8-13, 710/100-110, 710/126, 711/103, 381/312
• US Class Current: 710/10
• CPC Class Codes: G06F 12/0684 with feedback, e.g. presence or absence of unit detected by addressing, overflow detection
• CPC Class Codes: G06F 9/4411 Configuring for operating with peripheral devices; Loading of device drivers

Abstract

In accordance with embodiments of the invention, an electronic device including one or more controllers and one or more slave units is provided with a bus such as an I²C serial bus that connects the controllers and the slave units. The device further includes a secondary memory containing software drivers for a variety of different types of slave units, which can be present on the bus. The controller determines which types of slave units are actually present on the bus by sending, for each type of slave unit represented by a corresponding software driver in the secondary memory, a command via the bus using an address for the type. After determining which types of slave units are present on the bus, the controller loads corresponding software drivers from the secondary memory into a RAM, and using the loaded software drivers to initialize the slave units present on the bus.

Claims

1. A electronic device, comprising:

at least one controller;

at least one slave unit;

a bus connecting the at least one controller and the at least one slave unit and functioning in accordance with a protocol that supports individual addressing and acknowledging; and

a secondary memory containing software drivers for a plurality of different types of slave units;

wherein

the at least one controller initializes each at least one slave unit by sending a query over the bus for each type of slave unit in a predetermined group of types of slave units, retrieving a corresponding software driver for each at least one slave unit that responds to the query, and performing initialization operations using the software driver; and

the at least one controller and the at least one slave unit are connected only by the bus.

2. The device of claim 1, wherein the bus is an I²C bus.

3. The device of claim 1, wherein the secondary memory is an EEPROM.

4. The device of claim 1, wherein the secondary memory is a static RAM.

5. The device of claim 1, wherein the secondary memory is connected to the bus.

6. The device of claim 1, wherein the secondary memory is directly connected to the at least one controller.

7. The device of claim 1, wherein the query is a power down command.

8. The device of claim 1, wherein the query is a dummy command.

9. The device of claim 1, wherein the bus consists of two lines.

10. The device of claim 1, wherein the bus is a serial bus.

11. A method for configuring an electronic device including at least one controller, at least one slave unit, a bus connecting the at least one controller and the at least one slave unit, and a secondary memory containing software drivers for a plurality of different types of slave units, comprising the steps of:

sending a command via the bus using an address for a type of slave unit;

receiving an acknowledge signal from a slave unit on the bus when the slave unit is of the type indicated by the address;

repeating the steps of sending and receiving using an address for a different type of slave unit;

loading a software driver from the secondary memory for each type of slave unit from which an acknowledge signal was received into a random access memory in the at least one controller; and

initializing each slave unit on the bus using the loaded software drivers.

12. The method of claim 11, wherein the bus is an I²C bus.

13. The method of claim 12, further comprising the step of repeating the steps of sending and receiving using an address for a different type of slave unit until all addresses corresponding to the slave unit types of the software drivers in the secondary memory have been used.

14. The method of claim 13, wherein the steps of sending, receiving, loading and initializing are performed periodically while the electronic device is powered up.

15. The method of claim 13, wherein the command requires a slave unit that is present on the bus and whose type corresponds to the address used to send the command, to send an acknowledge signal via the bus.

16. The method of claim 14, further comprising the step of purging all software drivers from the random access memory of the at least one controller that correspond to slave unit types that are no longer present on the bus.

17. The method of claim 16, wherein the command is a dummy command.

18. The method of claim 16, wherein the command is a power up command.

19. The method of claim 16, wherein the command includes an instruction requiring a slave unit that is present on the bus and whose type corresponds to the address used to send the command, to provide information that further identifies the slave unit.

20. The method of claim 16, wherein the at least one controller maintains a configuration file identifying the slave units on the bus.

21. The method of claim 11, wherein the bus consists of two lines.

22. The method of claim 11, wherein the bus is a serial bus.

23. The method of claim 11, wherein the step of repeating is performed until a predetermined number of acknowledge signals have been received.