Questions from newbie

I'm trying to get a broad view of embedded stuff.

I got a series of (what I hope are not) 12 silly questions which I'm hoping to clear up. Here goes :

1) Are FPGAs essentially scaled up microcontrollers? That is they differ from microcontrollers in that they have more programmable gates and more memory space (?)

2) Why would someone use an FPGA over say a minil ATX form factor motherboard with a Pentium chip? What advantage does an FPGA offer over a regular mini motherboard with a microchip?

3) I keep calling it "mini motherboards with pentium chips". What is the proper term for it? PC/104 boards ??

4) How do FPGA differ from ASICS. I'm thinking FPGA are for more general purpose whie ASICS are for more specific purposes.

5) Is the method of programming an ASICS and FPGA radiacally different or similar?

6) Will FPGAs eventually drop in price and replace microcontrollers for many functions? (assuming size is not important)

7) Is DSP (digital signal processing) done on FPGAs or some other type of board?

8) Is embedded linux mostly loaded onto those mini boards with Pentium chips?

9) When people talk about embedded systems, are they mostly talking about microcontrollers, FPGAs, ASICS or mini motherboards with pentium chips?

10) Are mini motherboards often used in conjunction with custom designed boards with microcontrollers? e.g. the microcontroller board collects data and feeds that back to the mini motherboard. The mini motherboard processes data spits that info out to another board with a microcontroller which moves a stepper motor.

11) What kind of board are they using in my cable modem, DVD player, LCD screen?

12) Once I get comfortable with using a microcontroller, what would be the next step in learning? I'm thinking of learning more about using embedded linux on those mini mobos with pentium chips.

Last but not least, thank you for your time!

Reply to
zalzon
Loading thread data ...

zalzon wrote in news: snipped-for-privacy@4ax.com:

Absolutely not. They are logic gates that are field programmable.

No idea, since an FPGA isn't a motherboard or a Pentium chip. E.g. how do you add your new PCI card to a FPGA?

PC/104 are a particular form factor. So is mini and microATX. What "it" are you talking about?

ASICs are more like regular ICs. You cannot reprogram them like FPGAs. The two can be used interchangeably in many cases.

Yes, FPGAs you download you program into them and ASIC are manufactured by silicon fabrication houses.

Since they are a general solution, I don't see how they could be cheaper than a mass-produced, cost optimized CPU.

Sure I suppose.

I guess since those "mini" motherboards are just like regulare PC motherboards for the most part.

All of them but I typically think of it as microcontrollers. After all there's Windows XP Embedded (I kid you not).

I have no idea.

Probably a full custom board (e.g. not a PC mother board).

Get a Linux vendor supported evaluation boards.

--
- Mark ->
--
Reply to
Mark A. Odell

Hello zalster, Let's get some acronyms down first: FPGA = Field Programmable Gate Array ASIC = Application Specific Integrated Circuit Judging from your questions, it wasn't obvious that you knew what these acronyms meant. FPGAs are reprogrammable logic devices that allow you to place a chip on a board, then adjust the logic that the board performs by designing new logic that gets loaded, usually at powerup, into the FPGA. The programming for the FPGA logic usually resides in a seperate memory device, usually a serial EEPROM. I've never worked with ASICs, but I have the impression that they are exclusively used in high-volume applications.

FPGAs aren't microcontrollers. Microcontrollers execute a program and usually an FPGA is placed between a microcontroller and peripheral devices like RAM, EEPROM, or other devices like MPEG encoders. Microcontrollers have internal RAM, ROM, clock generators, and lots of registers that work in a certain, pre-ordained fashion. FPGAs might have some of these components, but not usually. Although there are some FPGAs that will allow you to load, for example, an 8051 core into them and then they look like an 8051 microcontroller. Is this confusing enough for you?

PC/104 is a form factor, an industry standard board size, something like

3" x 3" with standardized pinouts on their interfacing connectors. Some have Pentium processors, some have Power PC, or different processors. There are lots of PC/104 boards that don't have processors, but perform some other functions like digital or analog I/O, multiple RS-232 interfaces, LCD interfaces, and others. You can control PC/104 boards with embedded Linux or other operating systems like DOS, QNX, Nucleus, or others. PC/104 boards are usually used in industrial or military applications, so these boards are usually more pricy than other standardized form factors, but they can take more abuse from temperature variations, humidity, vibration, and other factors.

Most likely the boards in your cable modem and other consumer electronics are totally non-standard form factors. Open them up and take a look, just turn the power off beforehand.

If you are interested in learning about microcontrollers, I'd purchase an evaluation kit and test it out. I would start with an 8-bit or 16-bit architecture to keep things simpler. Believe me, an 8-bit microcontroller will keep you busy for a long time. Evaluation kits from Zilog or Phytec will cost you from $50 to $170.

Reply to
Bob F.

woah woah woah! slow down kid :)

Between a microcontroller and peripheral devices? What could possibly be going on between a microcontroller an peripheral device? ]

What would you say are FPGA's used for? I mean could you give me an example of when a peron might consider using an FPGA.

Very much thank you :)

Ah I see. Power PCs.. aren't those macintosh chips? How is it mac gets to be so popular? In desktop terms at least, PCs control almost all of the market.

never knew a board could run without a processor...

Copy that. QNX and stuff are for real time isn't it?

Though i wanted to start with AVR microcontrollers, some PIC fanatics influenced me into starting with Pics. I hope i made the right choice though looking at the message below of a newbie praising AVRs, my heart sinks a little. I have already ordered the PIC programmer. Avrfreaks sure looks like a great place for newbies.

Reply to
zalzon

I can't seem to get my head around fpga's. Do microcontrollers not have logic gates in them? Can't see what the difference is between programming a microprocessor/microcontroller and programming an FPGA.

It isn't a motherboard, and it isn't a chip. ........my mind has gone blank trying to figure out what they are :)

So then they are just like microcontrollers aren't they. You load a program in and they do whatever the program wants them to do.

Yes I'm aware.

Would it have a chip in there and if so what kind?

Copy that.

Thanks!

Reply to
zalzon

and

devices

Here's an example: You have a microcontroller with 32 address and 32 data lines, but various Chip Selects, and you also have an audio encoder chip with address/data lines, plus output enable, chip select, etc. lines. You will need some type of handshaking logic between the two devices in order to transfer data between them. You put the FPGA between the two devices and now you have an intermediary device that can flexibly be programmed to set up and maintain logic between the two devices. Now you can digitize your voice into an internet phone or whatever application you wanted.

like

Don't be deceived into thinking that PCs are the biggest market. The biggest market for microcontrollers is in the 4, 8, and 16-bit microcontrollers that go into automobiles, tools, consumer electronics. PCs and 32-bit microprocessors are something like 8% of the overall market. Most video game modules have more processing capability than the average desktop PC, plus they usually have 2,3, or 4 micros where a desktop PC has

1.

boards

are

take

Yes, real time is another topic for another day.

purchase

microcontroller

I've never worked with AVRs or PICs. I know that there are a lot of hobbyists that use them, but my OJT was with Intel 8051 microcontrollers. I like to have different sources and there are a lot of derivatives of the

8051 uC out there now.
Reply to
Bob F.

PC/104 is a form factor. It's like saying PCI or ISA. What he means is that there are lots of PC/104 cards with I/O devices on them that you can attach to a PC/104 CPU card.

Reply to
Gary Kato

You have a lot to learn...

No... they are mainly used in high end comms.... most of the telephone and internet runs on them.

Because they work.... MACs tend to have them majority of the professional graphics, film and music markets.

Any ISC or PCI card?

This is comp.arch.embedded....

AVR, PIC or 8051 are OK for beginners because they are inexpensive and there is a lot of information about for them.

Let's start again..

1 what is your background?

2 What to you want to do?

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

formatting link
\/\/ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Reply to
Chris Hills

zalzon wrote in news: snipped-for-privacy@4ax.com:

You did not. JTAG programmable and debuggable 8051's from Cygnal or MSP430's from Texas Instruments would have made your life much easier.

--
- Mark ->
--
Reply to
Mark A. Odell

Chris Hills wrote in news:639MuNAxCyh$ snipped-for-privacy@phaedsys.demon.co.uk:

Internet routers would be MIPS, not PowerPC right?

--
- Mark ->
--
Reply to
Mark A. Odell

zalzon wrote in news: snipped-for-privacy@4ax.com:

Go read some documents at

formatting link

Yes but *you* cannot change what the gates in the MCU do. You can in an FPGA. The MCU will always fetch programs and do with them what they are hardcoded to do. FPGAs can be "programmed" to provide a 32-bit latch, "reprogrammed" to provide a bus interface between other devices, or provide coprocessor-like computations.

No. With FPGAs you actually "change" the hardware connections inside the FPGA. With an MCU you just change the instruction stream that the poor-fixed-function MCU must blindly execute.

--
- Mark ->
--
Reply to
Mark A. Odell

An FPGA ic an IC containing a large number of logic gates and flip-flops that the user can "wire up" as required for his application. An FPGA can be used to replace a number of "normal" logic chips, greatly reducing the PC Board space required to perform a particular task.

An FPGA may be programmed by drawing schematic diagrams, just as you would design a circuit with normal TTL logic chips.

An ASIC (Application Specific Integrated Circuit) may start out as an FPGA. Once the equipment manufacturer decides he has the design correct, and will need a large number of identical parts, he may convert the FPGA design to ASIC, as the ASIC part will be much cheaper than the FPGA in large quantities.

Just to confuse you further, some large FPGAs can be "programmed" to emulate a processor.

As I understand it, to make a working PC/104 system you would stack several PC/104 boards together - one would have the processor, others would have I/O devices of various sorts.

--
Peter Bennett VE7CEI         
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html 
 Click to see the full signature
Reply to
Peter Bennett

In article , Mark A. Odell writes

The SDH stuiff I worked on for two of the worlds major comms compaines used PPC.

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

formatting link
\/\/ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Reply to
Chris Hills

In article , Mark A. Odell writes

Actually any of the 8051's would be a good idea.

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \/\/\/\/\ Chris Hills Staffs England /\/\/\/\/\ /\/\/ snipped-for-privacy@phaedsys.org

formatting link
\/\/ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/

Reply to
Chris Hills

It's very hard to give you an example without knowing what kind of background you have.

I guess the easiest answer to this would be: wherever a designer in the 80s would have used lots of individual logic gate ICs from the

74xxx series connected in some clever ways, today's designer will use an FPGA and program the clever connections into that.

And just like, in the very early days, people would sometimes go an build an entire CPU out of 74LS00 gates, for educational or even practical purposes, you can now go ahead and connect the tens of thousands of 74LS00 gates found in an FPGA to form a CPU.

So, get back to your original question: a FPGA can become a CPU, if you want to, but a CPU usually can't become an FPGA --- it can execute a program that simulates the behaviour of one, though.

--
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.
Reply to
Hans-Bernhard Broeker

I'm not new to FPGA's, but I am new to using them in a hobby environment. My prior experience was though commercial packages such as a research department of a largish company would have.

What's needed to be able to program an FPGA from the point of view of a hobbyist sitting at his computer at home, with a severely limited budget (only what he can scrounge away from the kids and his wife's shoe shopping)?

Fredderic

Reply to
Fredderic

BTW, what is the difference between FPGAs, CPLDs, GALs and PALs?

regards, Bernd

Reply to
Bernd Maier

He said it isn't "a Pentium chip". Pentium isn't the whole world you know, in fact it's a very small percentage of the total CPU market.

An FPGA is a chip, in which you can reprogram the interconnections between the logic gates. In a CPU you can load a program which performs logical operations, but you can't change the actual interconnections between the internal gates.

In the embedded Linux world, you'll find many X86 [i.e. pentium family] systems, but there is a large amount of stuff done on ARM and PPC as well.

When you simply need something that a PC can do in an embedded package, you might use an off the shelf X86 board[1], but when something special purpose is needed and you're designing your own board, there's often no advantage in sticking with X86, and processors more suited to embedded systems will have considerable benefits.

For example a project I recently worked on needed an embedded Linux system for which a new board was designed using the PPC 855T CPU. Because this chip has on-board ethernet, UARTs and hardware HDLC the board design was much simpler than if we'd used an X86 family chip.

[1] There is a wide range of ARM & PPC boards available too.
Reply to
Geoff McCaughan

"Bernd Maier" skrev i meddelandet news:bmcea4$j3nmf$ snipped-for-privacy@ID-68715.news.uni-berlin.de...

Some practical definitions.

PAL means Programmable Array Logic and contains typically

Reply to
Ulf Samuelsson

Are PLDs all obsolete now? Or getting obsolete?

Are PLDs all superseeded by microcontrollers/mobos with microchips/FPGA boards?

Reply to
zalzon

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.