--- title: "ASIP vs GPP and processor selection" subject: "Embedded System" chapter: 2 key: "semester_6/embedded_system:asip-vs-gpp-selection-issues" source: https://www.bctengineer.com/q/semester_6/embedded_system/asip-vs-gpp-selection-issues site: BCT Engineering --- # ASIP vs GPP and processor selection Embedded System · Chapter 2: Hardware Design Issues - Asked in: 2070 Magh, 8 marks - Video: [Unit No 1 10 Difference Between ASIP & GPP](https://www.youtube.com/watch?v=5MDYITKHaIQ) — @bhitronics - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/embedded_system/asip-vs-gpp-selection-issues - Whole chapter: https://www.bctengineer.com/md/semester_6/embedded_system/chapter-2 ## Question Differentiate between application specific instruction set processor and general purpose processor. Also discuss issues related to selection of a particular processor. ## Short answer GPPs serve any application with generic hardware; ASIPs are optimized for a domain with specialized instructions and on-chip peripherals, offering better performance and lower power for that domain. Selection issues include performance, memory, power, cost, I/O peripherals, real-time response, software tools, familiarity, availability, and time-to-market. ## Answer #### Difference between ASIP and GPP | Point | GPP | ASIP | |---|---|---| | Purpose | General computing, any application | Optimised for a class of applications | | Instruction set | General | Specialised instructions (MAC, bit-handling) | | Datapath | Generic ALU, register file | Custom functional units for the domain | | Performance | Average across tasks | High for target applications | | Power / cost | Higher for a given task | Lower for the intended task | | Peripherals | Mostly external | Many on chip | | Flexibility | High | Moderate | | Examples | Pentium, ARM Cortex-A | DSP, microcontroller, network processor | #### Issues in selecting a processor - **Performance:** clock speed, MIPS, instruction cycle, pipeline and word length. - **Memory:** program and data memory size, on-chip versus external. - **Power consumption:** sleep modes, battery life. - **Cost:** chip price and total cost including support chips. - **Peripherals and I/O:** timers, ADC, UART, SPI/I2C, interrupts and pin count. - **Real-time response:** interrupt latency and determinism. - **Software support:** compilers, debuggers, RTOS, library and tool-chain availability. - **Familiarity and reuse:** earlier code and engineer experience. - **Availability and quality:** supply continuity, temperature range and package. - **Time-to-market:** development kits and evaluation boards. The best choice is the processor that just meets the performance requirement at the lowest cost and power with adequate tool support. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. How does an ASIP differ from a GPP in design goal? A. ASIP is meant for any application; GPP is optimised for one class B. ASIP has no program memory; GPP has one C. ASIP is optimised for a class of applications; GPP is meant for any application D. ASIP always has a slower clock than a GPP Answer: C. An ASIP has specialised instructions and custom functional units for a domain, while a GPP is general and average across tasks. (Key point: ASIP purpose) 2. Which feature is typical of an ASIP rather than a GPP? A. Peripherals mostly external to the chip B. Highest flexibility C. Higher power and cost for a given task D. Specialised instructions such as MAC and bit-handling Answer: D. ASIPs add domain-specific instructions (MAC, bit handling) and custom functional units, with many peripherals on chip. (Key point: ASIP features) 3. Which group lists issues that a designer considers when selecting a processor? A. Performance, memory, power, cost, peripherals, software support B. Only clock speed and colour of the package C. Only the price of the chip D. Only the brand and the number of pins Answer: A. Selection weighs performance, memory, power, cost, peripherals, real-time response, tool support, reuse, availability and time-to-market. (Key point: Selection issues) 4. Why is software/tool-chain support a selection issue? A. It decides the clock frequency of the chip B. Compilers, debuggers and RTOS availability affect development time and effort C. It decides the pin count D. It removes the need for memory Answer: B. Good compilers, debuggers, RTOS and libraries shorten development, so they influence which processor is chosen. (Key point: Software support) ## Related in Embedded System - [ASIP versus general purpose processor](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Aasip-vs-gpp) — Embedded System, chapter 2 - [ASIP as compromise processor](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Aasip-compromise-gpp-spp) — Embedded System, chapter 2 - [Embedded vs general purpose computing](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Aembedded-vs-general-computing) — Embedded System, chapter 1 - [RTOS versus general-purpose OS](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Artos-vs-gpos) — Embedded System, chapter 6, asked 4× - [Fibonacci single-purpose processor](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Aspp-fibonacci) — Embedded System, chapter 2, asked 2× - [Single-purpose processor for power](https://www.bctengineer.com/question.md?key=semester_6%2Fembedded_system%3Aspp-power) — Embedded System, chapter 2, asked 2× ## Related in other subjects - [Centralized vs distributed; design issues](https://www.bctengineer.com/question.md?key=semester_7%2Fdistributed_system%3Acentralized-vs-distributed) — Distributed System, chapter 1 - [General river intake and site selection](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Ageneral-river-intake) — Water Supply Engineering, chapter 5, asked 3×