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Independent Internal I/O Bus
This application is a Continuation of U.S. patent application Ser. No. 10/803,030, filed Mar. 16,2004, "PROGRAMMABLE MICROCONTROLLER ARCHITECTURE (MIXED ANALOG/DIGITAL)" by Snyder, et al. now U.S. Pat. No. 7,221,187
RELATED U.S. APPLICATION
This application claims priority to the copending provisional U.S. patent application Ser. No. 60/243,798, entitled "Advanced Programmable Microcontroller Device," with filing date Oct. 26, 2000, and assigned to the assignee of the present application.
FIELD OF THE INVENTION
The present invention relates to the field of microcontrollers. More particularly, the present invention relates to the integration of programmable analog circuits and programmable digital circuits on a single semiconductor chip.
Microcontrollers may have embedded processors, memories and special function analog and digital circuits. Typical analog circuits found in prior art microcontrollers include Continuous Time (CT) amplifiers having preset functions with given functional parameters. For instance, a CT analog amplifier might be configured as a fixed function circuit, such as a voltage amplifier, in which certain parameters, such as gain or bandwidth might be altered by programming.
Switched Capacitor (SC) analog circuits are also frequently incorporated into microcontroller designs. SC analog circuits in prior art are somewhat more versatile than CT analog circuits in that it might be possible to alter both the circuit function as well as the parameters of the circuit function by programming. However, both CT and SC analog circuits found in current microcontrollers generally require programming before utilization, and neither can be dynamically programmed (programmed "on-the-fly").
In the conventional art, general purpose digital circuits are frequently included in a microcontroller implementation. Such digital circuits are pre-programmed to realize certain digital functions such as logical operations, arithmetical functions, counting, etc. These digital circuits are generally in the form of a Programmed Logic Array (PLA) or FPGA. Furthermore, such digital circuits that require pre-programming are generally not dynamically programmable (programmable "on-the-fly"). The main difficulty here is in the generality of such a digital circuit, which requires an excessive amount of digital logic, which in turn occupies a large area on a semiconductor chip as well as an increased cost of manufacturing.
Several other design considerations related to microcontroller utilization either go unaddressed, or require separate functionalities to enable them. For instance, existing designs do not offer a programmable analog circuit array with both CT analog circuits and SC analog circuits on the same semiconductor chip with a programmable array of digital circuits. As a result, realization of a function requiring complex communication between analog circuits and digital circuits often requires the use of multiple semiconductor chips. Further,
existing microcontroller realizations generally require preprogramming and cannot be dynamically programmed.
What is needed is a method and/or system which can be dynamically programmed to complete a complex communi
5 cation interface between analog circuits and digital circuits in order to realize a desired microcontroller circuit function. What is also needed is a method and/or system that can utilize both CT and SC analog circuits implemented along with digital circuits on a single semiconductor chip. Further, what
10 is needed is a method and/or system in which the functions and/or function parameters of the analog circuits and the digital circuits can be reconfigured by dynamic programming (programming "on-the-fly"). Further still, what is needed is a circuit and/or system in which a reduction of the digital logic
15 implemented to realize a dynamically programmable digital circuit results in a reduction in required semiconductor chip area.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a microcontroller consisting of programmable analog blocks and programmable digital blocks interconnected with a programmable interconnect structure fabricated on a single
25 semiconductor chip. Programmable System On-a-Chip (PSoC) architecture offers an excellent analog and digital interface that solves many design needs. The present design provides the complex communication interface between digital and analog blocks that can be reconfigured on-the-fly. The
30 programmable analog array with both Continuous Time (CT) analog blocks and Switched Capacitor (SC) analog blocks are realized on the same semiconductor chip with programmable digital blocks.
A microcontroller with analog/digital Programmable Sys
35 tern On-a-Chip (PSoC) architecture including multiple digital PSoC blocks and multiple analog PSoC blocks in a communication array having a programmable interconnect structure is described. The single chip design is implemented by integration of programmable digital and analog circuit
40 blocks that are able to communicate with each other. Robust analog and digital blocks that are flash memory programmable can be utilized to realize complex design applications that otherwise would require multiple chips and/or separate applications. The PSoC architecture includes a novel array
45 having programmable digital blocks that can communicate with programmable analog blocks using a programmable interconnect structure. The programmable analog array contains a complement of Continuous Time (CT) blocks and a complement of Switched Capacitor (SC) blocks that can
50 communicate together. The analog blocks consist of multiblocks that can communicate together. The analog blocks consist of multi-function circuits programmable for one or more different analog functions, and fixed function circuits programmable for a fixed function with variable parameters.
55 The digital blocks include standard multi-function circuits and enhanced circuits having functions not included in the standard digital circuits. The PSoC array is programmed by flash memory and programming allows dynamic reconfiguration. That is, "on-the-fly" reconfiguration of the PSoC
60 blocks is allowed. The programmable analog array with both Continuous Time analog blocks and Switched Capacitor analog blocks are offered on a single chip along with programmable digital blocks. The programmable interconnect structure provides for communication of input/output data
65 between all analog and digital blocks.
More specifically, a first embodiment of the present invention includes a number of programmable analog circuit
blocks configured to provide various analog functions, and a number of programmable digital circuit blocks configured to provide various digital functions. A programmable interconnect structure comprising a routing matrix and an independent bus provides coupling between analog circuit blocks, 5 digital circuit blocks and external devices. Flash memory is used to program the interconnect structure as well as the analog circuit blocks and the digital circuit blocks. Programming can be accomplished dynamically to reconfigure any of the programmable blocks or the interconnect structure. 10
A complement of Continuous Time (CT) analog circuit blocks and a complement of Switched Capacitor (SC) analog circuit blocks are configured to communicate with one another as well as with external devices by means of the interconnect structure. Dynamic or "on-the-fly" program- 15 ming of the interconnect structure is used to direct data between both analog circuit blocks and digital circuit blocks as well as any external devices coupled to the semiconductor chip. A number of the analog circuit blocks are multi-function circuits that can be reconfigured by dynamic programming 20 ("on-the-fly" programming) to perform a number of differing functions. Some of the analog circuit blocks are capable of only a single function, but dynamic or "on-the-fly" programming can reconfigure the parameters of the function. Standard digital circuit blocks are configured to perform various digital 25 operations including logical decisions and arithmetical computations. Enhanced digital circuit blocks are configured similarly to the standard digital circuit blocks and have additional digital functions available. Both standard and enhanced digital circuit blocks are reconfigurable by dynamic or "on- 30 the-fly" programming.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the architecture of the 35 Programmable System On-a-Chip (PsoC) according to the present invention.
FIG. 2 illustrates one embodiment of the hardware routing resources of the Programmable System On-a-Chip (PsoC) architecture according to the present invention. 40
FIG. 3 is a flow chart illustrating steps in a combined digital/analog operation possible with the Programmable System On-a-Chip (PsoC) according to the present invention.
FIG. 4 is a flow chart illustrating steps in a digital operation possible with the Programmable System On-a-Chip (PsoC) 45 according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred 50 embodiments of the invention, PSoC architecture (mixed analog/digital), examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these 55 embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous 60 specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, compo- 65 nents, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
NOTATION AND NOMENCLATURE
Some portions of the detailed descriptions which follow may be presented in terms of procedures, logic blocks, processing, and other symbolic representations of operations on data bits within a microcontroller, or other electronic device. These descriptions and representations are used by those skilled in the electronic arts to most effectively convey the substance of their work to others skilled in the art. A procedure, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical, electronic, or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in an electronic system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, bytes, values, elements, symbols, characters, terms, numbers, streams, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as "adjusting," "ascertaining," "calculating," "changing," "commanding," "communicating," "conducting," "controlling," "determining," "dividing," "executing," "forming," "generating," "intercommunicating," "monitoring," "multiplexing," "performing," "programming," "registering," "repeating," "sensing," "setting," "supplying," or the like, refer to the action and processes of microcontrollers, or similar intelligent electronic and/or microelectronic devices, that manipulate(s) and transform(s) data and signals represented as physical (electronic and electrical) quantities within the devices' registers and subcomponents into other data and signals similarly represented as physical quantities within the device subcomponents and registers and other such information storage, transmission or display capabilities.
Exemplary Circuits and Systems
The present invention provides an on-chip integration of programmable digital and analog circuit blocks in a microcontroller that are able to communicate with each other. FIG. 1 is a block diagram 100 illustrating the Programmable System On-a-Chip (PsoC) architecture composed of programmable analog blocks 121 that can communicate with programmable digital blocks 122 by means of a programmable interconnect structure 123 and a General Purpose I/O 124. This novel architecture allows a single chip solution to numerous complex activities that would otherwise require multiple chips or separate applications. The dashed line 120 encloses the four major components 121, 122, 123 and 124 constructed on the single semiconductor chip. An important aspect of the present invention is the integration of both programmable analog circuits and programmable digital circuits on the same semiconductor chip.
The Analog System on a Chip Block (SoCbloc) 121 is coupled 125 to the Programmable Interconnect 124, and it is also coupled to the Internal Address/Data Bus 130. In one embodiment of the present invention, the Analog SoCbloc 121 consists of four Analog Continuous Time (ACT) amplifiers, four type 1 Switched Capacitor (SCI) amplifiers and four type 2 Switched Capacitor (SC2) amplifiers, all of which are dynamically programmable. Dynamic programming allows for "on-the-fly" modification of analog amplifier fixed