Microcontrollers
Contents
Microcontrollers
First, a few definitions:
- a CPU is something that can execute software programs. The earliest CPUs were built out of many parts, but now most CPUs are microprocessors.
- a microprocessor is a kind of CPU that all fits on one integrated circuit. The earliest microprocessors, and some famous kinds of microprocessors still being made, fill the entire chip, and so require external RAM and ROM/FLASH memory. But now most CPUs sold are microcontrollers[1].
- A microcontroller is a kind of microprocessor that, in addition to the CPU, also includes RAM and ROM/FLASH memory on a single die/package.
A microcontroller is a little computer on a single Die/Package. The computer includes a CPU core, RAM, ROM/FLASH, and peripherals including UARTS, A/D converters, SPI, and I2C. Microcontrollers differ from microprocessors in that the microporcessors generally have bigger more powerful central processing units, but need support chips for ram, rom and other peripherals. Most modern microcontrollers use FLASH ram instead of a ROM so they can be programmed over and over. Many modern microcontrollers allow self-flashing to enable bootloading or a firmware update without pulling the chip from the circuit or using a programmer/debugger. Microcontrollers tend to be more optimizated for writting in assembly than PCs, but C and Basic are becoming more standard programming languages.
General
Many hobbyists use microcontrollers, sometimes even multiple microcontrollers, in their projects. Prices have fallen below $5 for the cheapest 32-bit microcontroller and below $1 for the cheapest 8-bit microcontroller.
I've written a little about the various kinds of microcontrollers at Wikibooks: Embedded Systems. --DavidCary 06:15, 10 March 2007 (PST)
About 55% of all CPUs sold in the world are 8-bit microcontrollers. Over 2 billion 8-bit microcontrollers were sold in 1997.[2]
(Anyone have more up-to-date statistics?)
Somebody always thinks their microcontroller is the best microcontroller, so we have listed all of them as best.
"PIC vs. AVR": "OK, I know what you people want. You want ultimate fighting, embedded E.E. style. You want to know WHICH IS BETTER, PIC OR AVR?"
Some notes on Microcontroller RS232 Communications
Microchip PIC
The best microcontroller.
- PIC Links A bunch of links to PIC based information.
- Microchip PIC 8 bit FLASH microcontrollers
- Microchip dsPIC/PIC24 16 bit FLASH microcontrollers ( DsPIC30F 5011 Development Board )
- Microchip PIC32 32 bit FLASH microcontrollers
External Links:
Microchip dsPIC
The best microcontroller.
Not quite sure how this is different from a PIC, I think that it has some digital signal processor capabilities. Someone know more and want to clue us in?
- Microchip dsPIC/PIC24 16 bit FLASH microcontrollers
- DsPIC30F 5011 Development Board
External Links:
Atmel AVR
The best microcontroller.
- Atmel AVR 8 bit FLASH microcontrollers
Development Boards
Development Boards are printed circuit boards that contain a microcontroller and enough circuirty ( sp later ) to get it going, typically at least some of the following: clock, voltage regulator, reset button, communications chip, buffer aplifiers, led's, prototyping area, and/or off chip connections. Sometimes the manufacturer of the chip sells development boards ( often called evaluation boards ).
Cypress PSoC
The best microcontroller.
- Cypress PSoC 8 bit FLASH microcontrollers.
External Links:
ARM
The best microcontroller.
LPC2103 Low cost 70MHz ARM7TDMI-S FLASH Microcontroller from Philips. The "$49" "Coridium ARMmite" does use this chip.
Other Needs to be Organized
- Main Page May have been a one man effort, now dropped. Has a bit of content that looks good.
