There were Bits of gossip about the demise of 8 and 16-bit processors are extraordinarily misrepresented. Distributed in ESD April 2003.
8/16 Bits
60% of all CPUs and MPUs are 8 bits; 16 sharp flavoring represent 15% of the market, with the much-ballyhooed 32-bit machines raising the back of the market at an insignificant 9%. As per a 2001 review, our 43% of our readers utilize PICmicro parts, 55% utilize 8051/52/251/AVR, 36% go for Motorola’s 68XX family and Zilog’s Z8/Z80/Z180 devices represent around 15%. These numbers add up to over 100% as a few people utilized more than one processor in that year. In the 16 bit world, 41% utilize 8086/186/96/196 devices and 21% utilize the 68HC12/16.
Most intriguing is that these designs, with the conceivable special case of the 68HC12/16, are 25 years of age. New outlines experience serious difficulties contending, most likely because of the abundance of help for the more established CPUs, and a huge pool of designers who are knowledgeable in applying the parts.
Despite the fact that 8 and 16-bit processors were at one time the all-inclusive figuring motor found in every single keen item, today they are utilized as a part of the domain of profoundly inserted applications, ones that commonly have a considerable measure of I/O. Peripherals are imperative, as confirm by the astounding number of variations for a few devices. Somewhere in the range of 200 distinctive 8051s offer for all intents and purposes any blend of I/O wanted.
Despite the fact that clocks, parallel bits, serial I/O and other customary capacities remain the staple of peripherals, today numerous devices offer refined exceptional reason capacities like LCD drivers and quick A/D converters.
Communications is vital to numerous even basic devices. On-chip I2C, not found on 32 sharp flavoring, is normal in the 8/16 bit world. CAN, in any case extremely well known particularly in Europe, is accessible. Indeed, even USB controllers exist on-chip, as in Hitachi’s H8S/2215.
Web bolster exists as on-board MACs (Media Access Controllers) on a couple of parts, outstandingly Zilog’s eZ80F91. Outsider sellers (e.g., CMX) give convention stacks to interface even the littlest processors to the ‘net.
Most interesting is the move to “virtual” peripherals. Triscend’s E5 is an 8031 encompassed by an FPGA; the creator arranges peripherals utilizing their apparatuses. Need four clocks and 3 serial ports? Alter the fringe blend to precisely your necessities.
Cypress’ 8 bit PSoC (Programmable System-on-Chip) is comparable, yet enables the creator to rethink the fringe blend as the program runs. Or maybe like a shapeshifter the gadget adjusts to changing necessities progressively. Simple squares let you arrange devices that are generally off-contribute outer circuitry, as programmable pickup enhancers and channels.
Memory
Memory necessities are soaring in all processing applications. Modest parts with unimportant many bytes of ROM are as yet normal and very helpful for straightforward applications. More perplexing ones are being served by the developing capacity of new CPUs. Zilog’s eZ80, for example, is a 8 severe that delivers up to 16 Mb.
Microcontrollers are at last moving from OTP (One Time Programmable – an EPROM with no deletion window) to Flash. In spite of the fact that Flash remains a more costly innovation, having the capacity to program a gadget after it’s fastened onto the circuit board lessens producing costs. As program sizes develop so do bugs; refreshing code without disassembling an item is an effective contention for Flash.
Indeed, even the revered Z8, the core of most TV remote controls, is accessible with 64k of on-chip Flash and another 4K of RAM.
At the point when “security” is utilized we promptly think about another Federal division, or of network vulnerabilities. However in the implanted world a large number of us must secure our protected innovation, the millions spent making an item’s code base. A few CPUs are tending to this need by making it unimaginable, or if nothing else to a great degree costly, to peruse out the code put away in the CPU’s Flash. An illustration is Dallas’ DS2252, a 8051-good gadget that stores program code scrambled with a 64 bit key. The SDI stick, short for Self Destruct Input (no joking!), will, if stated, erase the key. A circuit that recognizes altering can drive SDI, leaving the item cerebrum dead however figuring out safe.
Crushing Size and Power
I saw a Motorola 68HC05 running off of two lemons wired in arrangement 20 years prior. From that point, forward batteries haven’t enhanced much, yet the requirement for compact registering has detonated. Most processors now offer low power modes. Our February issue contains a decent article (Software Matters for Power Consumption) about utilizing these modes adequately.
5-volt parts are still extremely normal, yet don’t loan themselves well to devices running from a couple of AA cells. CPUs today keep running from an extensive variety of voltages: 3, 3.3, 3.5, 2.4 and even 1.8. Lower voltage diminishes control (estimated in amp-hours) sucked from the battery.
A plenty of low-control modes are accessible. In rest mode, Epson’s S1C88 family utilizes 0.3 microamps (run of the mill). Wakeful, it needs just 14 ma at 32 KHz, and 2 ma at 4 MHz. 8-bit H8 devices utilize a scarcely quantifiable 0.1 mama when resting, and a little more than one microamp at 32 KHz.
Modest power needs are a piece of building little frameworks. It’s difficult to trust that a couple of decades back a little PC measured tons; the present SMT innovation put processors and microcontrollers into bundles whose pins show up as fine as spider webs.
Infineon’s C163-L 16 bit microcontroller, as is run of the mill of little frame factor devices, arrives in a 100 stick TQFP (Thin Quad Flat Pack) arrangement, estimating only 14 mm on a side, with 0.5 mm lead pitch (leads too little to check whether you wear bifocals). At 1.4 mm thick it’s useable in super-thin applications like PCMCIA cards. Rabbitt Semiconductor’s Rabbit 3000 arrives in an assortment of bundles, including a 10 mm square TFBGA (Thin Fine Pitch Ball Grid Array) only 1.2 mm thick.
Flag Processing
Simple will never leave, however, fashioners appear to be determined to pushing the computerized some portion of a circuit as near a sensor as could be allowed. This is mostly conceivable on the grounds that we can make computerized channels in programming, an undertaking that consumes tremendous measures of preparing power.
TI spearheaded DSP microchips. Their TMS3201x are 16 bit DSP devices utilized as a part of an enormous scope of items.
Be that as it may, in a bend, now Microchip is making DSCs (Digital Signal Controllers). This is a group of 16 bit DSP microcontrollers. All accompany on-chip Flash, RAM, A/Ds, PWM, and even EEPROM. They run from little (16k of Flash) to very nearly 200k.
Different devices, similar to TI’s MSP430, are bisexuals, conventional CSIC CPUs with the expansion of the DSP’s MAC (Multiply and Accumulate) direction. Macintosh is a guideline that performs both an increase and an expansion in a solitary direction cycle, which significantly speeds numerous flag handling calculations.
Rundown
The tremendous expansion of processors makes it likely one precisely suited for your application is accessible. What’s more, if not – well, exploit the advances that let you plan your own particular fringe blend.
Figure on low expenses – several pennies for some little devices in high volumes, a couple of bucks for the higher-end processors.
The 8 and 16-bit world has never been more beneficial.
