42Bastian Schick wrote:> On Fri, 28 Apr 2006 12:54:28 +0200, "Ulf Samuelsson" > <ulf@a-t-m-e-l.com> wrote: > > >> and maybe make anything with a timer a microcontroller. > > PPCs have a decrementer, which acts as timer. I am not sure, but > I strongly believe you can find it as well in "desktop" PPCs. >Modern x86 devices have all sorts of internal timers and counters as well, and they don't count as microcontrollers by any standards. I think identifying microcontrollers and microprocessors is a bit like identifying spam and ham - you have some rules that contribute points one way or the other, with your final decision based on a total score. A single fixed timer gives a little score, but several flexible timers (especially with dedicated pins) gives a much bigger score.
Two Ethernet MACs in a new DualCore ARM Microcontroller
Started by ●April 25, 2006
Reply by ●April 28, 20062006-04-28
Reply by ●April 28, 20062006-04-28
"David Brown" <david@westcontrol.removethisbit.com> skrev i meddelandet news:445253e5$1@news.wineasy.se...> 42Bastian Schick wrote: >> On Fri, 28 Apr 2006 12:54:28 +0200, "Ulf Samuelsson" >> <ulf@a-t-m-e-l.com> wrote: >> >> >>> and maybe make anything with a timer a microcontroller. >> >> PPCs have a decrementer, which acts as timer. I am not sure, but >> I strongly believe you can find it as well in "desktop" PPCs. >> > > Modern x86 devices have all sorts of internal timers and counters as well, > and they don't count as microcontrollers by any standards. >Sorted out by rule 1 ;-) to avoid this discussion. Anything *optimized* for workstations are unlikely to count as microcontrollers. Also, timer to do instruction count etc, does not count. It should at least generate a periodic interrupt so you can .> I think identifying microcontrollers and microprocessors is a bit like > identifying spam and ham - you have some rules that contribute points one > way or the other, with your final decision based on a total score. A > single fixed timer gives a little score, but several flexible timers > (especially with dedicated pins) gives a much bigger score. >In a way, but I think you can reach a point where there is no doubt that it is a microcontroller. An ATtiny13 with 1kB Flash , 1 timer and 6 I/O's is no less of a microcontroller than an ATmega2560 with 256 kB of flash, loads of timers and serial ports. It is significantly more a microcontroller than an i80386DX -- Best Regards, Ulf Samuelsson This is intended to be my personal opinion which may, or may bot be shared by my employer Atmel Nordic AB
Reply by ●April 28, 20062006-04-28
Ulf Samuelsson wrote:> "Hans-Bernhard Broeker" <broeker@physik.rwth-aachen.de> skrev i meddelandet > news:4befoaF11698sU1@news.dfncis.de... > >>Ulf Samuelsson <ulf@a-t-m-e-l.com> wrote: >> >> >>>I think any definition should be rule based. >> >>Yes. So here's my approach: >> >>It's a microcontroller only if >> >>1) it's a "micro", i.e. a programmable CPU of some sort, which comes as >> a single part. >> >>2) it's a "controller", i.e. it can actually control *something*: it >> has at least one input, and reacts to it on at least one >> output in a programmable way. Data bus doesn't count as I/O, here. >> >>3) It works all by itself, with *no* extra parts except for a very few >> exceptions, such as power supply and an external oscillator/quartz. >> >>The only point really open to discussion is whether code memory goes >>on the exception list of necessary extra parts, or not. Here's where >>the idea of a "family of microcontrollers" becomes useful. A >>candidate that fails to have internal code memory can still be counted >>as a microcontroller if it's just one member of a larger family >>including devices that really are microcontrollers. >> >>This should be limited to closely related chips. One might want to >>require that there's a fully drop-in replacement for the candidate >>chip that has all the same features, except the need for external code >>memory. >> >>-- > > > > So the 8031 would be a micro, but the AT91RM9200 would not be a micro > according to this rule. > If Atmel released an AT91RM9200 with internal flash, then suddenly the > AT91RM9200 > would change status from microprocessor to microcontroller. > > My gut feeling says, the AT91RM9200 IS a microcontroller and any good set of > rules needs to end up in that chips that feels like a microcontroller should be > microcontroller according to the rules.But this fails your Rule 2 _and_ Rule 6 ? Zilog are reasonably clear on this, and Philips generally make the clear distinction that their Microprocessor-leaning devices are either "ROMless" uC, or "FLASHless" uC. Vendors marketing depts will want to 'coat tail' on other lines, and companies structures may have different divisions handling Microprocessors, which then gives some motivation to 'label by division' rather than any credible or physical yardstick. I guess the best we can hope for is that these are clearly called ROMless/FLASHless, and that the marketing guys refrain from calling them 'System on Chip solutions', where physically more than one chip is actually needed to get a working system ! -jg
Reply by ●April 28, 20062006-04-28
"Ulf Samuelsson" <ulf@a-t-m-e-l.com> wrote in message news:e2sss3$da1$1@emma.aioe.org...> Rule 1) Anything running late versions of Windows (CE does not count > here) is not a microcontroller > I am going to ignore all comment about Geode...I think you mean something like: if it uses less than 1 Watt, runs at less than 200 (or maybe 100) Mhz, has fewer than 144 pins, doesn't have a cache or MMU, has less than 1MByte flash, 1-128KB on-chip RAM, doesn't need external chips other than flash/ROM/DRAM, costs less than $25 then it is definitely a micro controller. You can argue about exact the numbers of course. Otherwise just about all current ARMs up to 1GHz are "micro controllers" using your definition. Micro controllers typically use small packages, are clocked below 100Mhz and don't cost much. They can't run standard Windows or Linux indeed. High-end processors with MMU, lots of SRAM/cache, with many peripherals (including advanced stuff like audio/video accelerators) are called "application processors".> Rule 2) Anything with a serial communication channel, is a > microcontrollerJust about all CPUs have several serial communication channels, like Hypertransport, USB, Ethernet, JTAG. It would need to be UART, CAN, SPI, or I2C in order to qualify as a micro controller.> Rule 3) Anything with minimum 1 timer capable of providing a periodic > interrupt is a microcontrollerAll modern CPUs have this, including performance counters. Having a watchdog timer would be more micro controller specific. A low interrupt latency (< 25 cycles) and vectored interrupts are clearly micro controller area too (CPUs with caches usually need a minimum of 100 cycles).> Rule 4) Anything without internal code memory (cache does not count > here) is not a microcontrollerIt is more common to have on-chip SRAM than ROM or flash. It would be better to say that it isn't a micro controller if doesn't use flash or ROM to execute most of its code (copying parts of the flash to SRAM for fast execution is OK, using a flash just for booting isn't).> Rule 5) Anything without minimum 1 programmable I/O pin is not a > microcontroller > Rule 6) Anyting REQUIRING a "companion" chip, is not a microcontroller > Clarification: > A companion chip is defined as a chip which if integrated > with a microprocessor > would make the microprocessor a microcontroller > Exception: A pure memory is not a "companion" chip.That's reasonable. Wilco
Reply by ●April 28, 20062006-04-28
The m32c, amusingly enough, has a single chip mode, a memory expansion mode, and a microprocessor mode. In microprocessor mode, the internal flash is disabled, giving nearly all of the address space to external devices. Single-chip mode reconfigures the CPU bus pins to be GPIO pins.
Reply by ●April 29, 20062006-04-29
Wilco Dijkstra wrote:> "Ulf Samuelsson" <ulf@a-t-m-e-l.com> wrote in message > news:e2sss3$da1$1@emma.aioe.org... > >> Rule 1) Anything running late versions of Windows (CE does not >> count here) is not a microcontroller >> I am going to ignore all comment about Geode... > > I think you mean something like: if it uses less than 1 Watt, runs at > less than 200 (or maybe 100) Mhz, has fewer than 144 pins, doesn't > have > a cache or MMU, has less than 1MByte flash, 1-128KB on-chip RAM, > doesn't need external chips other than flash/ROM/DRAM, costs less > than $25 then it is definitely a micro controller. You can argue about > exact the numbers of course.No, it is the philosophy behind design decisions that disqualifies the parts. I consider a 533 MHz PXA255 to be a (ROMless) microcontroller. It is no less a microcontroller than an 8031. Rule 1 is a sloppy rule, I admit, but it achieve my purpose which is to have a set of rules which, if followed, results in that everything I have a gut feel IS a microcontroller, is identified as a microcontroller. I do not think MMU, Cache, large internal memory, large pincount disqualifies chips. FPSLIC has 256 pins, and is still a micro. AT91FR40162 (while MCP) has 2 MB Flash/256kB SRAM and is still a micro. ARM9s with cache/MMU still are micros, especially with the new flash based ARM9s coming are still micros. I cant see that if you have two chips, with identical flash/peripherals, and one is using an ARM7 and the other is using ARM946/926, that the first should qual as a micro and not the second.> Otherwise just about all current ARMs up to 1GHz are "micro > controllers" using your definition. Micro controllers typically use > small packages, are clocked below 100Mhz and don't cost much. They > can't run standard > Windows or Linux indeed. High-end processors with MMU, lots of > SRAM/cache, with many peripherals (including advanced stuff like > audio/video accelerators) are called "application processors".Maybe, but I think an application processor can be amicrcontroller as well.>> Rule 2) Anything with a serial communication channel, is a >> microcontroller > > > Just about all CPUs have several serial communication channels, > like Hypertransport, USB, Ethernet, JTAG. It would need to be UART, > CAN, SPI, or I2C in order to qualify as a micro controller. >No, the high end PowerPCs, SPARCses and x86ses don't. These are Microprocessors. BTW: While Hypertransport may be serial, I do not count bus expansion as a criteria that makes something a microcontroller. Nor do I count On Chip Debugging interfaces. USB/Ethernet I do feel counts.>> Rule 3) Anything with minimum 1 timer capable of providing a >> periodic interrupt is a microcontroller > > All modern CPUs have this, including performance counters.Performance counters does not count (forgive the pun). If you can schedule a task at a certain time, that definitely increase your "microcontrollerness". Gathering statistics don't.> Having a watchdog timer would be more micro controller specific. A low > interrupt latency (< 25 cycles) and vectored interrupts are clearly > micro controller area too (CPUs with caches usually need a minimum of > 100 cycles).So the 8051 was not a micro then... No watch dog and at 12 cycles per instruction, I doubt it will fulfil the < 25 cycles. I think these count more as desirable features in a microcontroller, rather than something which decides whether they are microcontrollers or not. A microcontroller can be designed to be fast or it can be designed to be slow. It is OK to be slow, when you are controlling a slow task. An alarm clock, does not need to have very fast interrupts.> >> Rule 4) Anything without internal code memory (cache does not >> count here) is not a microcontroller > > It is more common to have on-chip SRAM than ROM or flash. It would > be better to say that it isn't a micro controller if doesn't use flash orROM> to execute most of its code (copying parts of the flash to SRAM for > fast execution is OK, using a flash just for booting isn't).Disagree, the AT76C712 AVR based USB <-> Serial Bridge, I definitely put in the microcontroller camp. It boots from a ROM, copies the application code from a serial flash into the 16-22kB internal SRAM and then runs at 48 MHz from the SRAM. USB device, dual UART, SPI , Timers. Same goes for the AT91RM3400. Boot ROM, copy to internal 96 kB SRAM. No external bus. loads of serial ports, timers, USB etc. Can't say that is not a micro.> >> Rule 5) Anything without minimum 1 programmable I/O pin is not a >> microcontroller >> Rule 6) Anyting REQUIRING a "companion" chip, is not a >> microcontroller Clarification: >> A companion chip is defined as a chip which if >> integrated with a microprocessor >> would make the microprocessor a microcontroller >> Exception: A pure memory is not a "companion" chip. > > That's reasonable. > > Wilco-- Best Regards, Ulf Samuelsson ulf@a-t-m-e-l.com This message is intended to be my own personal view and it may or may not be shared by my employer Atmel Nordic AB
Reply by ●April 29, 20062006-04-29
Ulf Samuelsson wrote:> Wilco Dijkstra wrote: > >>"Ulf Samuelsson" <ulf@a-t-m-e-l.com> wrote in message > >>>Rule 4) Anything without internal code memory (cache does not >>>count here) is not a microcontroller >> >>It is more common to have on-chip SRAM than ROM or flash. It would >>be better to say that it isn't a micro controller if doesn't use flash or >>ROM to execute most of its code (copying parts of the flash to SRAM for >>fast execution is OK, using a flash just for booting isn't). > > > Disagree, the AT76C712 AVR based USB <-> Serial Bridge, I definitely put in > the microcontroller camp. > It boots from a ROM, copies the application code from a serial flash > into the 16-22kB internal SRAM and then runs at 48 MHz from the SRAM. > USB device, dual UART, SPI , Timers. > > Same goes for the AT91RM3400. > Boot ROM, copy to internal 96 kB SRAM. > No external bus. loads of serial ports, timers, USB etc. > Can't say that is not a micro.You are both right; what it needs is a qualifier that defines the TYPE of Code memory : Thus we have FLASH uC / ROMless uC ( or FLASHless uC ), or RAMloaded uC, or ROM uC etc. RAMloaded uC ( and the DSPs that are calling themselves DSCs ) are becomming more common, and Boot from serial memory has rather less design impact than a 32 bit SDRAM bus. One reason is the poor flash speeds, another is the higher process cost of FLASH, but OnChip RAM for CODE is a valid uC design choice. Once the CODE fetch at runtime goes (mostly) OFF-CHIP, that's when it shifts => Microprocessor, as then the CODE memory is defined not by the ChipVendor, but by the users design choice. About here is also when the PCB layers hike, and the EMC testing from all those BUS CODE fetches, become an issue.... -jg
Reply by ●April 29, 20062006-04-29
>> Same goes for the AT91RM3400. >> Boot ROM, copy to internal 96 kB SRAM. >> No external bus. loads of serial ports, timers, USB etc. >> Can't say that is not a micro. > > You are both right; what it needs is a qualifier that defines > the TYPE of Code memory : > Thus we have FLASH uC / ROMless uC ( or FLASHless uC ), > or RAMloaded uC, or ROM uC etc. > > RAMloaded uC ( and the DSPs that are calling themselves DSCs ) > are becomming more common, and Boot from serial memory has rather > less design impact than a 32 bit SDRAM bus. > > One reason is the poor flash speeds, another is the higher > process cost of FLASH, but OnChip RAM for CODE is a valid uC designchoice.> > Once the CODE fetch at runtime goes (mostly) OFF-CHIP, that's > when it shifts => Microprocessor, as then the CODE memory is defined > not by the ChipVendor, but by the users design choice. >Then the 8031 is not a microcontroller. Any set of rules needs to work so that chips generally accepted as microcontroller are shown to be microcontrollers if the rules are applied to their definition.> About here is also when the PCB layers hike, and the EMC testing > from all those BUS CODE fetches, become an issue.... > > -jg-- Best Regards, Ulf Samuelsson ulf@a-t-m-e-l.com This message is intended to be my own personal view and it may or may not be shared by my employer Atmel Nordic AB
Reply by ●April 29, 20062006-04-29
Ulf Samuelsson wrote:>>>Same goes for the AT91RM3400. >>>Boot ROM, copy to internal 96 kB SRAM. >>>No external bus. loads of serial ports, timers, USB etc. >>>Can't say that is not a micro. >> >>You are both right; what it needs is a qualifier that defines >>the TYPE of Code memory : >>Thus we have FLASH uC / ROMless uC ( or FLASHless uC ), >>or RAMloaded uC, or ROM uC etc. >> >>RAMloaded uC ( and the DSPs that are calling themselves DSCs ) >>are becomming more common, and Boot from serial memory has rather >>less design impact than a 32 bit SDRAM bus. >> >>One reason is the poor flash speeds, another is the higher >>process cost of FLASH, but OnChip RAM for CODE is a valid uC design > > choice. > >>Once the CODE fetch at runtime goes (mostly) OFF-CHIP, that's >>when it shifts => Microprocessor, as then the CODE memory is defined >>not by the ChipVendor, but by the users design choice. >> > > > Then the 8031 is not a microcontroller.That's why you need the CODE qualifier, and trying to do without it will always fail on some cases! The correct classifcation is then : 8031 : ROMless Microcontroller 8051 : ROM Microcontroller 8351 : ROM Microcontroller (some vendors) 8751 : EPROM or OTP Microcontroller 8951 : FLASH Microcontroller xx : RAMload Microcontroller - See Cypress, Infineon, Atmel.... etc... Very simple, and a designer knows at a glance, what sort of PCB, and production flow, they will be working with. -jg> Any set of rules needs to work so that chips generally accepted as > microcontroller > are shown to be microcontrollers if the rules are applied to their > definition. > > >>About here is also when the PCB layers hike, and the EMC testing >>from all those BUS CODE fetches, become an issue.... >> >>-jg > >
Reply by ●April 29, 20062006-04-29
>> >> Then the 8031 is not a microcontroller. > > That's why you need the CODE qualifier, and trying to do without it > will always fail on some cases! >Here are the rules again. Rule 1) Anything running late versions of Windows (CE does not count here) is not a microcontroller I am going to ignore all comment about Geode... Rule 2) Anything with a serial communication channel, is a microcontroller Rule 3) Anything with minimum 1 timer capable of providing a periodic interrupt is a microcontroller Rule 4) Anything without internal code memory (cache does not count here) is not a microcontroller Rule 5) Anything without minimum 1 programmable I/O pin is not a microcontroller Rule 6) Anyting REQUIRING a "companion" chip, is not a microcontroller Clarification: A companion chip is defined as a chip which if integrated with a microprocessor would make the microprocessor a microcontroller Exception: A pure memory is not a "companion" chip. ... Rule n) It is a microcontroller> The correct classifcation is then : > > 8031 : ROMless Microcontroller > 8051 : ROM Microcontroller > 8351 : ROM Microcontroller (some vendors) > 8751 : EPROM or OTP Microcontroller > 8951 : FLASH Microcontroller > xx : RAMload Microcontroller - See Cypress, Infineon, Atmel.... >All these will be microcontrollers according to Rule (2) Since rule parsing is stopped when the decision is made, rule (4) is never reached, so all of above will be classified as microcontrollers. I do not see the problem. If you do not have a timer or a serial port, and no internal code memory, then you are not a microcontroller. If you have no timer, no serial port, no I/O but do have some internal code memory then you are not a microcontroller.> etc... > > > -jg-- Best Regards, Ulf Samuelsson ulf@a-t-m-e-l.com This message is intended to be my own personal view and it may or may not be shared by my employer Atmel Nordic AB
