Configurable input/output interface for a microcontroller

• US 6,825,689 B1
• Filed: 09/14/2001
• Issued: 11/30/2004
• Est. Priority Date: 10/26/2000
• Status: Expired due to Term

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Snyder, Warren
• Primary Examiner(s): Tran, Anh Q.
• Application Number:
  US09/953,423
• Time in Patent Office: 1,173 Days
• Field of Search: 326/37-41
• US Class Current: 326/41
• CPC Class Codes: G06F 13/4072 Drivers or receivers G06F13/4086 takes precedence; for multistate logic circuits H03K19/0002

Abstract

A configurable input/output interface for a microcontroller. The present invention is an input/output (I/O) pin with a configurable interface to a microprocessor, and to a global mapping which selectively couples functional units on the microcontroller with the I/O pin. The I/O pin can be selectively coupled to the global mapping or to the microprocessor on each clock cycle. The mapping configuration selectively couples a different functional unit or units of the microcontroller to access the I/O pin on each clock cycle. The interface between the I/O pin and the rest of the system can be dynamically configured by software created or modified by a user, or by hardware. The present invention facilitates repositioning pin locations on a microcontroller because it is a software modification rather than a hardware modification. The present invention further enables the microcontroller functions to be configured by the user rather than by the microcontroller vendor.

Claims

1. In a microcontroller having a microprocessor, an input/output interface comprising:

a) an input/output pin;

b) a global mapping system for selectively coupling said input/output pin to a plurality of functional units of said microcontroller; and

c) a configuration system for defining a system function for said input/output pin and for selectively coupling said input/output pin to one of said microprocessor and to said global mapping system.

2. The microcontroller as recited in claim 1, wherein said global mapping system and said configuration system further comprise a plurality of registers.

3. The microcontroller as recited in claim 2, wherein said microprocessor can dynamically configure said plurality of registers of said global mapping system and said configuration system.

4. The microcontroller as recited in claim 3, wherein said configuration of said global mapping system and said configuration system are supplied by a control program.

5. The microcontroller as recited in claim 1, wherein said global mapping system further comprises an input global mapping for receiving data and an output global mapping for transmitting data.

6. A circuit comprising:

a) an input/output pin coupled with a microprocessor, a global mapping system, and a plurality of configuration registers for defining a system function of said circuit and for selectively coupling said input/output pin to one of said microprocessor and said global mapping system; and

b) a plurality of functional units coupled to said global mapping system.

7. The circuit as recited in claim 6, wherein said plurality of configuration registers selectively couple said input/output pin to said microprocessor and said global mapping system.

8. The circuit as recited in claim 6, wherein said plurality of configuration registers can be dynamically reconfigured.

9. The circuit as recited in claim 6, wherein said global mapping system further comprises a plurality of registers for selectively coupling said input/output pin to said plurality of functional units.

10. The circuit as recited in claim 9, wherein said plurality of registers of said global mapping system can be dynamically reconfigured.

11. A method for providing a configurable input/output interface for a microcontroller comprising:

a) coupling an input/output pin to a microprocessor and a global mapping system;

b) coupling said global mapping system to a plurality of functional units of said microcontroller; and

c) utilizing a configuration system to selectively couple said input/output pin to one of said microprocessor and said global mapping system.

12. The method for providing a configurable input/output interface for a microcontroller as recited in claim 11, wherein step a) further comprises providing a configuration system for selectively coupling said microprocessor to said global mapping system.

13. The configuration system as recited in claim 12 further comprising a plurality of registers which can be dynamically reconfigured.

14. The method for providing a configurable input/output interface for a microcontroller as recited in claim 11, wherein said global mapping system selectively couples said input/output pin to said plurality of functional units.

15. The method for providing a configurable input/output interface for a microcontroller as recited claim 14, wherein said global mapping system further comprises a plurality of registers which can be dynamically reconfigured.