A digital signal controller (DSC) can be thought of as a hybrid of microcontroller

Microcontroller

A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...

s and digital signal processor

Digital signal processor

A digital signal processor is a specialized microprocessor with an architecture optimized for the fast operational needs of digital signal processing.-Typical characteristics:...

s (DSPs). Like microcontrollers, DSCs have fast interrupt

Interrupt

In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....

 responses, offer control-oriented peripheral

Peripheral

A peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....

s like PWM

Pulse-width modulation

Pulse-width modulation , or pulse-duration modulation , is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches....

s and watchdog timer

Watchdog timer

A watchdog timer is a computer hardware or software timer that triggers a system reset or other corrective action if the main program, due to some fault condition, such as a hang, neglects to regularly service the watchdog A watchdog timer (or computer operating properly (COP) timer) is a computer...

s, and are usually programmed using the C programming language

C (programming language)

C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....

, although they can be programmed using the device's native assembly language

Assembly language

An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...

. On the DSP side, they incorporate features found on most DSPs such as single-cycle multiply–accumulate (MAC) units, barrel shifter

Barrel shifter

A barrel shifter is a digital circuit that can shift a data word by a specified number of bits in one clock cycle. It can be implemented as a sequence of multiplexers , and in such an implementation the output of one mux is connected to the input of the next mux in a way that depends on the shift...

s, and large accumulator

Accumulator (computing)

In a computer's central processing unit , an accumulator is a register in which intermediate arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation to main memory, perhaps only to be read right back again for...

s. Not all vendors have adopted the term DSC. The term was first introduced by Microchip Technology

Microchip Technology

Microchip Technology is an American manufacturer of microcontroller, memory and analog semiconductors. Its products include microcontrollers , Serial EEPROM devices, Serial SRAM devices, KEELOQ devices, radio frequency devices, thermal, power and battery management analog devices, as well as...

 in 2002 with the launch of their 6000 series DSCs and subsequently adopted by most, but not all DSC vendors. For example, Infineon and Renesas refer to their DSCs as microcontrollers.)

DSCs are used in a wide range of applications, but the majority go into motor control, power conversion, and sensor processing applications. Currently DSCs are being marketed as green technologies for their potential to reduce power consumption in electric motors and power supplies.

In order of market share, the top three DSC vendors are Texas Instruments

Texas Instruments

Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...

, Freescale, and Microchip Technology

Microchip Technology

Microchip Technology is an American manufacturer of microcontroller, memory and analog semiconductors. Its products include microcontrollers , Serial EEPROM devices, Serial SRAM devices, KEELOQ devices, radio frequency devices, thermal, power and battery management analog devices, as well as...

, according to market research firm Forward Concepts (2007). These three companies dominate the DSC market, with other vendors such as Infineon and Renesas taking a smaller slice of the pie.

DSC Chips

NOTE: Data is from 07/2007 and table currently only includes offering from the top 3 DSC vendors.

Vendor	Device	Clock Speed (MHz)	Flash (kB Kilobyte The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information... )	PWM channels, resolution, duty cycle
Microchip	dsPIC30F	30	6–144	4–8 (16 bit Bit A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states... s, 1 or 16.5 ns depending on part)
	dsPIC33F	40	12–256	8 (16 bits, 12.5 ns)
Texas Instruments	TMS320F280x	60–100	32–256	16 PWM (13 bits, 150 ps)
	TMS320LF240x	40	16–64	7–16 PWM (11 bits, 150 ps)
Freescale	MC56F83x	60	48–280	12 PWM (15 bits, 10 ns)
	MC56F80x	32	12–64	5–6 PWM (15 bits, 10 ns)
	MC56F81x	40	40–572	12 PWM (15 bits, 10 ns)

DSC Software Offerings

DSCs, like microcontrollers and DSPs, require software support. There are a growing number of software packages that offer the features required by both DSP applications and microcontroller applications. With a broader set of requirements, software solutions are more rare. They require: development tools, DSP libraries, optimization for DSP processing, fast interrupt handling, multi-threading and a tiny footprint.