Site Home Archive Home FAQ Home How to search the Archive How to Navigate the Archive
Compare FPGA features and resources
Threads starting:
Authors:A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
I check 10k ALTERA 5v on the speed of 140 MHz. Works!! But I did all design in AHDL and in some critical places need to define CLB placement manualy. CLIQUE some times does not help. Good luck Lev Razamat - PHASECOM Inc.Article: 10126
Tom Meagher wrote: > > allard jean-marc wrote in message <3544D8ED.25D66CD1@hol.fr>... > >Tom Meagher wrote: > >> > ... > ... > >> > > > >Synthesis tools I used (Synopsys, Compass RIP) have a command to specify > >multicycle paths. > >With synopsys, the command is 'set_multicycle_path'. Are you sure that > >your tool doesn't have such a common feature ? > >This command answer your 2 questions since clk_ena is out of the > >multicycle > >path. > > > >jean-Marc > > Yes, this is true, there is a multi-cycle path command for Galileo and > Synplify(see the excerpts > below), but I interpret this to be on a signal by signal, or register by > register basis, > not for an entire instantiated sub-component, several levels down in the > hierarchy, which > might have hundreds of signals and registers. > > And, even if one specified all the signals in the sub-component as > multi-cycle, > which seems rather tedious, I don't see how this forces the clock enables to > be connected > to the synthesized DFFE's. Am I missing something here? Maybe you can do this: Synthesize alone the block for which all internal paths are double cycle paths. Specifies for this block a clock of 12.5 Mhz and put a constraint on the arrival time of clk_ena so that clk_ena is tied close to your DFF. For example, says that clk_ena changes 5 ns before the rising clock edge. The synthesys tool will not necessary connect the clk_ena to the enable of yours FF but close to it and this is what you want. Then synthesize the upper hierarchy blocks with a clock of 25 Mhz with a "set_dont_touch" on the 12.5 Mhz block. If you find a better solution, could you please send it to me. Jean-MarcArticle: 10127
Dave Hawkins wrote: > I have an application where I want to operate on either > a 62.5MHz or 125MHz clock rate sample stream. > > Could anyone that has used FPGAs with high I/O data rates > comment on what they would consider would be the highest > data rate that, say, a 3.3V Altera Flex 10k130 could handle > on its I/O pins? > > I am considering having a 62.5MHz clock and a 125MHz clock. > Then having a 62.5MHz clock rate data stream multiplexed by > 2 on-board where operations on the data are performed at 125MHz. > Doubling the clock rate on-board reduces the required logic by > a factor of four for my application. > I will not comment on Altera, but you definitely can do this in Xilinx XC4000XL. I recently designed, built, and demonstrated a working copy of a complete frequency counter in an XC4002XL-09 that counts up to 420 MHz, admittedly without using any global clocks. Icc for the whole counter, including time-base and 6-digit LCD display, at 100 MHz input frequency is less than 10 mA. We have looked at ( but not completed yet ) the design of a 155-MHz multi-channel demultiplexer, say eight independent clock and data inputs, each to be reduced to a more manageable 39 MHz . There is no doubt that it will meet worst-case speed requirements. The beauty of segmented-routing FPGAs is that you can run small sections extremely fast without causing problems and power consumption all over the chip. Peter Alfke, Xilinx ApplicationsArticle: 10128
Hal Murray wrote in message <6i2ldd$gou@src-news.pa.dec.com>... > >Yes, but... Is there a location that corresponds >to the flip-reset-ploarity bit and is it documented? >[if so, where] > > There are specific locations for each size PROM. For the 17128, the locations are 0x4000 - 0x4003. You either fill these locations with 0x00 or 0xff to specify polarity. From the top of my head, 0x00 corresponds to RESET (low active) / OE (high active). The following line may be added to the MCS file to force these locations low: :0440000000000000BC But you still have to manually do this, one way or the other. Xilinx ignores this problem unless you are using their programmer. If they have addressed it, I have completely missed their solution. -- "PITCHERS.BAT found: delete DH.SYS? (Y/y)" Michael Ellis first initial last name at pesa dot you know whatArticle: 10129
staylor@dspsystems.com wrote: <snip> > You may also find that having two cloks like that causes a problem. If the > data is ever to be passed between them you would be better off to just use the > faster clock and disable the slower registers every other clock cycle. The > logic required to pass data between to clocks of unknown phase, and your will > be regardless of what precautions you take, is fairly complex compared to > using a single flip flop set to toggle as a clock enable to registers running > fast. > I am curious why you say two clocks will necessarily be out of phase. To interface to the asynchronous SRAMs I will use, I intended to use a doubled clock to generate a latched WE signal to avoid the delay problems discussed on another thread. Since some standard clock drivers create a doubled clock automatically, I had planned on using that. Will those clocks drift with respect to each other over time? Douglas Clayton -- Douglas_Clayton@fore.com FORE Systems hardware-engineer-in-training I don't speak for FORE.Article: 10130
Hi everybody, I am interested in getting some information/opinions on prototyping boards for Xilinx chips. I was looking at getting a cheap prototyping board for a Xilinx XC4010PC84 FPGA. From the Xilinx web page, I have found two companies that produce what appear to be suitable boards: 1) APS-X84 FPGA Test Board from Associated Professional Systems (APS) 2) XS40 Prototyping Board from X Engineering Software Systems (XESS) My minimum requirements are a standalone board with a socket for the Xilinx chip, a socket for a serial PROM (although I would also be happy with a parallel EPROM) and access to some of the I/O pins on the Xilinx chip. Both products offer a lot more than my minimum requirements. I have tried to read most of the documentation that is given by the respective companies. Some of my remaining questions are: - How easy is it to get up and running with the boards. They both appear to come with custom download S/W. - Has anybody had any bad (or good) experiences with either of the boards. - What are typical delivery/shipping times for the boards. Do they arrive when expected or are there delays. - Are the boards fairly rugged, for example, being able to hold out well under the physical abuse of a typical university environment. (assuming of course that noboby blows the chips up) - Any other information related to the two boards, or any other cheap boards that you know of, would also be useful. I am somewhat of a novice in this area and so don't really know what are the right questions to ask. I also have a related question concerning S/W tools. My development software is running on a workstation (Sun Solaris). Can I generate a configuration file on my workstation, copy it to my PC, and then download it to the card, or do I need to do some tweaking of the configuration file. I am using the XactStep tools (in order to be able to use the older chips). Thanks, ZeljkoArticle: 10131
Anyone have luck doing a 150MHz design using an FPGA?? Any suggestions on which FPGA might do the job? QuickLogic seems to have fast parts. Any comments on these parts? Thanks for your input, Tom --------------------------------------- Tom Karabinas ASIC Design Manager Sun Microsystems Computer Corporation email: tom.karabinas@eng.sun.comArticle: 10132
The output file is Intel Hex. Very easy to load. The Xilinx people will give you the format if you want it. All EPROM programmers accept Intel Hex. Simon ---------------------------------------------------------------------------------------------------------------------------------------------- zblazek@kasami.UVic.CA (Zeljko Blazek) wrote: > >Hi everybody, > >I am interested in getting some information/opinions on prototyping >boards for Xilinx chips. > >I was looking at getting a cheap prototyping board for a Xilinx XC4010PC84 >FPGA. From the Xilinx web page, I have found two companies that produce >what appear to be suitable boards: > > 1) APS-X84 FPGA Test Board from Associated Professional Systems (APS) > > 2) XS40 Prototyping Board from X Engineering Software Systems (XESS) > > >My minimum requirements are a standalone board with a socket for the Xilinx >chip, a socket for a serial PROM (although I would also be happy with a >parallel EPROM) and access to some of the I/O pins on the Xilinx chip. Both >products offer a lot more than my minimum requirements. > >I have tried to read most of the documentation that is given by the >respective companies. Some of my remaining questions are: > > - How easy is it to get up and running with the boards. They both > appear to come with custom download S/W. > > - Has anybody had any bad (or good) experiences with either of the > boards. > > - What are typical delivery/shipping times for the boards. Do they > arrive when expected or are there delays. > > - Are the boards fairly rugged, for example, being able to hold out > well under the physical abuse of a typical university environment. > (assuming of course that noboby blows the chips up) > > - Any other information related to the two boards, or any other cheap > boards that you know of, would also be useful. I am somewhat of a > novice in this area and so don't really know what are the right > questions to ask. > > >I also have a related question concerning S/W tools. My development >software is running on a workstation (Sun Solaris). Can I generate >a configuration file on my workstation, copy it to my PC, and then >download it to the card, or do I need to do some tweaking of the >configuration file. I am using the XactStep tools (in order to >be able to use the older chips). > > >Thanks, > >Zeljko > Opinions expressed herein are solely my own and may or may not reflect my opinion at this particular time or any other.Article: 10133
Zeljko Blazek wrote in message <6i5j46$1heo$1@uvaix7e1.comp.UVic.CA>... > [snip] > > - Any other information related to the two boards, or any other cheap > boards that you know of, would also be useful. I am somewhat of a > novice in this area and so don't really know what are the right > questions to ask. [snip] You seemed to have found the two simplest boards that I know of. The Programmable Logic Jump Station maintains a fairly comprehensive list of available boards at http://www.optimagic.com/boards.html. ----------------------------------------------------------- Steven K. Knapp OptiMagic, Inc. -- "Great Designs Happen 'OptiMagic'-ally" E-mail: sknapp@optimagic.com Web: http://www.optimagic.com -----------------------------------------------------------Article: 10134
As Title.Article: 10135
In article <35464CEE.6BC2@fore.com>, Douglas Clayton <dclayton@fore.com> wrote: > > I am curious why you say two clocks will necessarily be out of phase. To > interface to the asynchronous SRAMs I will use, I intended to use a > doubled clock to generate a latched WE signal to avoid the delay > problems discussed on another thread. Since some standard clock drivers > create a doubled clock automatically, I had planned on using that. Will > those clocks drift with respect to each other over time? > Douglas, The clocks will only drift if the source of the clocks drift. The problem will be that the delays in the FPGA may not be symetrical. Since you won't know internally which leads, even being able to externally alter the phase won't help. Why not just use a flip/flop to cause the slow registers to only update every other clock cycle? That way your entire design is synchronous to a single clock. Besides, simulation is far more complex, if even possible with two clocks if you pass data between them. I recall getting message to that effect when I tried it. You can run at any speed you want by having clock enables divided further. Your design will take more power and generate more heat, but not enough to make it worth the hassle two clocks will cause. Scott Taylor - DSP Fibre Channel Systems -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10136
Channing Wen wrote: > > As Title. Less cells than what ? There was a trick Intel used, on the C51, which made use of an extra BIT on Shifter length, rather than a separate 4 Bit State separate counter - On TX, this bit is loaded H, L's are shifted IN, and when ALL bits are Lo, you have finished ( and done the stop bit ) - jg -- ======= Manufacturers of Serious Design Tools for uC and PLD ========= = Specialists in Development tools for C51 cored controllers = Leaders in Rapid Application Development SW for C51 uC = Ask for our Controller & Tools selector Guides = mailto:DesignTools@xtra.co.nz Subject : Selc51ToolsArticle: 10137
>RESET (low active) / OE (high active). The following line may be added to >the MCS file to force these locations low: > >:0440000000000000BC Very smart! I completely forgot one *should* be able to simply add a line, with an arbitrary (but valid) load address, to an intel hex file. One just hopes that the hex loader code of whatever is reading the file does it properly... Peter. Return address is invalid to help stop junk mail. E-mail replies to zX80@digiYserve.com but remove the X and the Y.Article: 10138
>I recently designed, built, and demonstrated a working copy of a >complete frequency counter in an XC4002XL-09 that counts up to 420 MHz, >admittedly without using any global clocks. Peter, Did you use a ripple counter to achieve this ? Peter. Return address is invalid to help stop junk mail. E-mail replies to zX80@digiYserve.com but remove the X and the Y.Article: 10139
> >Hi, > > > >I am working on an XC4025E FPGA with Synopsys (UNIX version). > > > >I would like to write some data in a SRAM at each edge of my clock, and > >for this I must delayed my Write Enable signal from 4 or 5 ns? > > > >Could you give me some ideas to introduce a delay in Xilinx FPGA? > >Is it possible to use a clock buffer (BUFGS) on my Write Enable signal > >to do this? Hi! We had faced a similar problem when we wanted to do perform successive RD/WRs. We had used the CLK as the CE to the SRAM to get it working. But I'm sure your problem would have been solved by ORing the WE with the CLK as suggested by someone earlier. Bye, Neeraj Nayak. -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10140
Scott, Referring to the Altera data book (or "dsf10K.pdf" file) I interpret page 35 a little differently. Figure 6 implies that the ENA input into the register is configurably shared with the DATA1 input to the LUT, implying the existence of a separate, high-speed clock enable path in the primitive architecture. (Otherwise, why even bother with a clock enable at all, eh?) Indeed, my Altera FAE, Steve Kliman, confirms the intent of this as being a high-speed clock gate, independently of the LUT. The bad news, as you correctly point out, is that you are then reduced to a 3 input LUT. With respect to AHDL, I agree. In fact we have some large MAX9000 series designs in AHDL, where we instantiate DFFE's and connect the .ENA inputs up to a sub-clock pulse train. One loses this with a behavioural VHDL description. With regards to scrutinizing the .RPT file: This becomes extremely tedious very quickly because the names get so badly "spaghettied" and lost almost immediately. In fact, even though it is yet another level farther away from the actual device, the .VHO file has more naming information that the .RPT file does, and the DFFE connections are easier to follow (although relating stuff back to the source code is still non-trivial). But, the answer is, yes, the ENA pins to the DFFE's are driven combinatorially. I suppose the ENA input is used by the synthesis tool to take advantage of the implied feedback from the output, and does indeed save a level of logic. Unfortunately, this precludes it's use as a clock qualifier. There is sort of a Catch-22 effect, though, isn't there? I mean, I want a dedicated clock enable because the logic is too slow to settle in one clock cycle, but is the logic too slow because of the extra levels of logic incurred by the clock enable? (In fact, though, in this application I do need to use the clock enable to match the core state machine logic to the data rate anyway). The synchronous reset is tied off to '0' at a higher level for the reasons you mention. Best Regards, Tom Meagher (last name pronounced "mar", don't ask why...) tomm@icshou.com staylor@dspsystems.com wrote in message <6i3v6o$q18$1@nnrp1.dejanews.com>... >In article <6i2aug$f4s$1@supernews.com>, > "Tom Meagher" <tomm@icshou.com> wrote: >> >> We have something on the order of 10,000 lines of VHDL, which synthesizes >> down to about 85-90% of an Altera 10K70 (the -3 speed grade is our target >> part). Now, it is neither possible nor necessary for the entire design to >> meet the 25 MHz system clock requirement after place and route. This is >> because the most complex stuff only needs to process data at half system >> clock speed. >> >> Therefore, we partition off the slow-speed blocks and desire to connect the >> "CE" inputs to all the "DFFE" flip flops to a 12.5 MHz (sys clock divided by >> 2) clock enable signal. > >Tom, > >A couple of points. First, the 10k logic elements use one of the 4 lookup >table inputs for the clock enable (1998 Databook page 35). The I/O elements >have true clock enables from global signals (1998 databook page 49), but the >logic elements do not. Since you thyen only have 3 LUT inputs, you are more >likely to have cascaded logic elements feeding the DFFEs. A non-global reset >or preset takes another LUT input if you are using it. Under certain >conditions global presets take a LUT input. Using both clear and preset always >uses a LUT input. Having a synchronous load capability also uses a LUT input. >The carry output uses one also. Some combinations are mutually exclusive. > >In effect the clock enable for a 10k logic element is really just a 4th input >to the lookup table which would then imply a fifth [not shown] input, feedback >from the Q output of the DFF. I/O elements can only have a single signal feed >the D input though so that probably won't help. Since a logic element clock >enable isn't global, there are routing delays associated with it. Using >schematic entry wouldn't help. You are already telling Maxplus 2 to use the >clock enable, you are just expecting too much from it. > >You need to look in the .RPT file and see how the DFFEs are synthesized. My >opinion is that this is a case where AHDL would give you better results. Does >VHDL retain the symbolic names in the .RPT file? (AHDL does if you do not use >funtions) If you have some high speed signals and some that are static or >lower speed you can cause the slower ones to have the longer delay paths by >coding the preceeding logic cells yourself. > >I have been asking Altera to provide a way to do this at a higher level for >several years, but so far nothing. > >Scott Taylor - DSP Fibre Channel Systems > >-----== Posted via Deja News, The Leader in Internet Discussion ==----- >http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10141
Scott, 100MHz makes me both jealous and depressed! I would be happy to get my protocol parser and TDMA dual ported RAM's to work at 25MHz (sigh). Individual sub-components seem to be OK, but when everything goes together into a 10K70 device that is much over 65% full, then look out, stuff never seems to fly as fast as one thinks it should... Tom Meagher staylor@dspsystems.com wrote in message <6i52v4$pm8$1@nnrp1.dejanews.com>... >In article <6i2aug$f4s$1@supernews.com>#1/1, > >I read your message again this morning. At 12.5MHz and 25MHz what you are >doing should be a breeze. I do it at 60-100MHz frequently, even with slower >speed grades (*see note). Look at your .RPT file and trace one of the logic >elements that don't work. You could even post the relavent parts. You will >probably find that the clock enable is going through several layers of >combinatorial logic, and/or the rest of the data to the LUT is also. > >* Note: The speed listed in the Altera databook is for 16 bit synchronous >counters. No tricks like lookahead carries are used to achieve those numbers. >I have several times gotten higher speeds, validated by their simulator and >timing analyser, by quite a bit. > >Scott Taylor - DSP Fibre Channel Systems >Article: 10142
staylor@dspsystems.com wrote: > > Douglas, > > The clocks will only drift if the source of the clocks drift. The problem will > be that the delays in the FPGA may not be symetrical. Since you won't know > internally which leads, even being able to externally alter the phase won't > help. Why not just use a flip/flop to cause the slow registers to only update > every other clock cycle? That way your entire design is synchronous to a > single clock. Besides, simulation is far more complex, if even possible with > two clocks if you pass data between them. I recall getting message to that > effect when I tried it. I'm afraid I still don't understand. What I had intended to do was have one clock as an input to a clock driver which would then output several versions of that clock as well as a clockx2 signal. My question is, aren't those clocks guaranteed to be within some small variation in phase? This doubled clock will not even be in my main FPGA, but in a smaller (and faster) controller CPLD, used solely to generate a low WE. The fact that it is in a register rather than being an AND'd clock means that the WE will go high much sooner after the clock--meaning the data hold issue will be less important. clock +-----------+ +------ (20MHz) ________| |___________| write -----------+ +------ (clocked with clock)|_______________________| clockx2 --+ +-----+ +-----+ +----- (40MHz) |_____| |_____| |_____| /WE ------------------------+ +---------- (clocked with clockx2) |__________| As you can see, I am relying on the fact that both clocks are in phase. For my 20MHz clock, this gives me a WE signal of 25 ns plus a hold time of 5-7 ns (certainly faster than my FPGA). If I just AND'd the clock with the write signal, I would get delays more like 15 ns, too long for me to guarantee the address/data will be stable. Is there something I am missing? (Maybe I should just use ZBT synchronous SRAMs. :) Douglas Clayton -- Douglas_Clayton@fore.com FORE Systems Hardware Engineer-in-training I don't speak for FORE.Article: 10143
Tom, You should check out Actel's new SX family of FPGAs. They have a 4.0 nS clk-out and a 320MHz maximum clock frequency for the fastest device. You should visit our site at www.actel.com and you can download the datasheet. You can also download a free version of our Designer Lite software that allows you to do designs up to 16K gates. Hope this helps! Regards, Michael Lee ActelCorp In article <354652A0.EDC111E@eng.sun.com>, tom karabinas <tom.karabinas@eng.sun.com> wrote: > > Anyone have luck doing a 150MHz design using an FPGA?? > > Any suggestions on which FPGA might do the job? > > QuickLogic seems to have fast parts. Any comments on these parts? > > Thanks for your input, > > Tom > > --------------------------------------- > Tom Karabinas > ASIC Design Manager > Sun Microsystems Computer Corporation > email: tom.karabinas@eng.sun.com > -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10144
Have you looked at DynaChip ?? They have ECL FPGA's. Bill Seiler DIVXArticle: 10145
Hello, As you , i was looking for some USB infos: hardware, software, drivers. Please , read them at my web page : http://www.angelfire.com/ok/jpbelin/Top_page.html Hope this will help. PepitoArticle: 10146
On Sat, 25 Apr 98 20:46:25 GMT, Steve@s-deweynospam.demon.co.uk (Steve Dewey) wrote: >Err... Let me clarify: I have not attempted to port VHDL code developed >in Altera's Maxplus to Cypress' Warp. I was asking whether it would be feasible >or not. Theoretically yes, VHDL is SUPPOSED to be a standard, but in practice, this is extremely unlikely. Vendors sometimes use odd libraries or constructs, so when you move your code to an independent tool you may find that it won't compile first time. >For a given piece of VHDL code, do the mega-bucks tools, e.g. Synopsys, >Exemplar, Synplicity actually implement it using fewer chip resources >than the standard Altera tools ? I understand that the implementation of VHDL Mega-bucks? I guess that depends on what your engineering teams' time costs you, what being late to market will cost you, and what having to use a bigger faster part will cost you in production. However wrt those three vendors, the answer is YES they will produce smaller, and faster results in many cases. If they didn't do things better than the vendor's tools then nobody would be buying them (would they?). Of course, if the design is 'small', then you may not necessarily need all the horse-power on offer from the third party vendors to produce an acceptable result. >may be more complete, and the software able to target multiple vendors >(but only with the vendors back-end tools...). No problem there then. If you have vendor independent tools, no FPGA vendor worth dealing with is going to give you an argument about back-end tools when you have a live project. It simply isn't a gamble they can afford to take, because you can just go elsewhere. When I was selling Lucent, we used to give away evals (no bitstream) to anyone with 3rd party synthesis tools. If the silicon was right for the particular design metrics, the deal was simple: First order for silicon means the bitstream license turned on for free. I can't guarantee that a disti/rep might not try to squeeze you for the tools, but a quick scream at the local sales office that you'll just go use brand X instead should put that right. Of course, if the potential revenue stream is considered too small, they might not want to play. Look at QuickLogic, they don't muck about. Their entire back end tools are available for free, no strings as far as I'm aware. <snip> StuartArticle: 10147
In article <6i7cbr$68q$1@supernews.com>#1/1, "Tom Meagher" <tomm@icshou.com> wrote: > > Scott, > 100MHz makes me both jealous and depressed! I would be happy to get my > protocol parser and TDMA dual ported RAM's to work at 25MHz (sigh). > Individual sub-components seem to be OK, but when everything goes together > into a 10K70 device that is much over 65% full, then look out, stuff never > seems to fly as fast as one thinks it should... > Tom, My off the cuff response would be that is because you are writing high level syntax and expecting the compiler and fitter to know the difference between critical and non-critical signals. If you have 10 inputs and only 2 are critical, how is the compiler/fitter to know which ones are critical. I don't know how true it still is, but Altera used to use alphabetical ordering. Try placing A-Z on the front of critical signal names to see if that helps. Since symbolic names are lost early in partitioned projects, I suspect the same is true of VHDL. In that case the names will have little or no effect. VHDL to me is an improvement in the wrong direction. People want portability, and they want performance too. I think VHDL is a long way from being able to offer both. Pick your vendor, even if it is on a project by project basis and write the code to fit the architecture. You will get higher performance and more logic in a smaller lower speed grade device. Since I commonly run as fast as the fastest speed grade will allow, I rarely have that option. While larger devices can usually be gotten in the same speed grades, routing delays, especially when soft buffers are inserted, make them appear slower. Scott Taylor - DSP Fibre Channel Systems -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10148
In article <6i7c07$16d$1@usenet11.supernews.com>#1/1, "Tom Meagher" <tomm@icshou.com> wrote: > > Scott, > Referring to the Altera data book (or "dsf10K.pdf" file) I interpret page 35 > a little differently. Figure 6 implies that the ENA input into the register > is configurably shared with the DATA1 input to the LUT, implying the > existence of a separate, high-speed clock enable path in the primitive > architecture. (Otherwise, why even bother with a clock enable at all, eh?) > Tom, Please disregard my comments on e-mail. Apparently the e-mail got to me more quickly than your post did. I have included my e-mail response. I added the part regarding soft buffer insertion. I know this is a VHDL newsgroup, but I think at times high level languages are a step backward. I guess I was a little unclear. I didn't mean to imply that data1 didn't become a clock enable, only that it still has the variable routing delays associated with it, including soft buffer insertion delays, the same as the other LUT inputs, compared to the I/O element that has a global clock enable capability that does not have such variable delays. All you gain is elimination of the LUT delays. What this means is that the setup and hold times will not be the same across the device. You can verify this by having 5 logic elements. Place them in the four corners and the middle and use the timing analyser to determine the maximum frequency. I could be wrong, but I have been reading and using Altera databooks and parts for over 8 years and have learned to read between the lines. >> But, the answer is, yes, the ENA pins to the DFFE's are driven combinatorially.<< Each logic element in the combinatorial path to the clock enable adds to the variable routing delays. That is likely to be what is causing some of your problems. By using AHDL and doing all combinatorial fan-in manually you can steer the highest speed signals into the shortest paths. I personally would use an entry method that enables the report file to be utilized. A couple of times I modularized my code and used functions. Each time the loss of ability to use the report file outweighed the advantage. Now I just partition the code in the file instead. That way I can still come back later and cut and paste previous work into new designs. The files get long, but todays editors don't seem to mind. %************** % % C40 Comm Port % %************** % code %*********************% % Some other function % %*********************% code etc. I think you are a living and example I commonly cite. You will spend more time simulating and wrestling with VHDL to get it to do what you want than it would take to just do it in AHDL. Either that, or you will end up using a faster speed device than you really need. For a 1 or 2 application that might be the better choice, though I find eventually I regret it for some reason or another when I come back and have to make changes. If you do finally get VHDL to work, every time you make a [major] change you will have to do it all over again. Like higher level programming languages VHDL requires interpretation to comform to specific devices and architectures. That usually results in compromised performance. AHDL on the other hand allows you to write code in a form that has a direct translation to the architecture. What You See Is What You Get, WYSIWYG, assuming that is the option you select, I always do. I say that knowing it isn't always true, at times the software people at Altera seem to feel they know better than I what I want, even when I select WYSIWYG. One to two years later they find they don't in fact know better and stop interpreting, only to do it with some other feature. Scott Taylor - DSP Fibre Channel Systems -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreadingArticle: 10149
WORK SMARTER, NOT HARDER ARE YOU READY TO GET $50,000 IN 5 WEEKS ON WITH JUST $6.00 ??? The fact that so many people have taken the time to post to 250 newsgroups or more should convince you that this really works!!! BE HONEST AND FAIR and you will make money! LOTS OF MONEY!!! (Sure is a lot of mail though! Heck, there’s $20.00 bucks just in recycled paper!) THANKS FOR READING ******************************************************* PLEASE READ ON ABOUT SOMEONE WHO IS SUCCESSFUL AT THIS AND HOW TO BE SUCCESSFUL ALSO: ******************************************************* A little while back, I was browsing these newsgroups, just like you are now, and came across an article similar to this that said you could make thousands of dollars within weeks with only an initial investment of $6.00 ! So I thought," Yeah, right, this must be a scam", but like most of us, I was curious, so I kept reading. Anyway, it said that you send..$1.00 to each of the 6 names and address stated in the article. You then place your own name and address in the bottom of the list at #6, and post the article in at least 200 newsgroups. (There are literally thousands of newsgroups) No catch, that was it. The main difference between this system and others is that you have a mailing list of 6 instead of 5... This means that your average gain will be approximately. 15 times higher!!! So after thinking it over and talking to a few people first, I thought, what the heck, trying it is just like the lottery in a way, except you keep plunking down bucks after bucks over several weeks looking to hit the big one, only ending up with maybe winning $50.00 after spending $75.00 in the long run. I figured what have I got to lose except 6 stamps and $6.00, right? Like most of us, I was a little skeptical, no make that really skeptical and a little worried about the legal aspects of it all. So I checked it out with the U.S. Post Office (1-800-725-2161) and they confirmed that it is indeed legal! Then I cracked open the cookie jar and invested the measly $6.00........ Well GUESS WHAT!!!...I prayed and sweated for what I thought was an eternity but low and behold... within 7 days, I started getting money in the mail! I was shocked! Amused even! I still figured it would end soon and didn't give it another thought, maybe I could buy another computer with the little bit of money, if that. But the money just kept coming in. In my first week, I made about $20.00 to $30.00 dollars. By the end of the second week I had made a total of over $1,000.00!!!!!! In the third week I had over $10,000.00 and it's still growing. This is now my fourth week and I have made a total of just over $42,000.00 and it's still coming in rapidly....... It's certainly worth $6.00, and 6 stamps, I spent more than that on the lottery!! Let me tell you how this works and most importantly, why it works....also, make sure you print a copy of this article NOW, so you can get the information off of it as you need it. The process is very simple and consists of 3 easy steps: STEP 1: Get 6 separate pieces of paper and write the following on each piece of paper: "PLEASE PUT ME ON YOUR MAILING LIST." "$1.00 - US DOLLAR PROCESSING FEE ENCLOSED Now get 6 US $1.00 bills (or equivalent in your local currency) and place ONE inside EACH of the 6 pieces of paper so the bill will not be seen through the envelope to prevent thievery. Next, place one paper in each of the 6 envelopes and seal them. You should now have 6 sealed envelopes, each with a piece of paper stating the above phrase, your name and address, and a $1.00 bill. What you are doing is creating a service by this. THIS IS ABSOLUTELY LEGAL! Mail the 6 envelopes to the following addresses: #1 G A Gram 104 E. Fairview Ave #238 Meridian, ID 83642 #2 Daniel M. P. P.O. Box 3001 Reston, VA 201701 USA #3 P Ward 740 E. Republic Salina, KS 67401 USA #4 Michael 12302 E Appaloosa PL Scottsdale, AZ 85259 #5 S. Perkins 14001 Saint Leo Ct. Orlando, FL 32826 #6 Patrick 2100 Rebsamen Park Rd. #412 Little Rock, AR 72202 STEP 2: Now take the #1 name off the list that you see above, move the other names up (6 becomes 5, 5 becomes 4, etc...) and add YOUR Name as number 6 on the list. STEP 3: Change anything you need to, but try to keep this article as close to original as possible. Now, post your amended article to at least 200 newsgroups. (I think there is close to 34,000 groups) All you need is 200, but remember, the more you post, the more money you make! Don't know HOW to post in the newsgroups? Well do exactly the following: ----------------------------------------------- DIRECTIONS - HOW TO POST TO NEWSGROUPS: ----------------------------------------------- Step 1. You do not need to re-type this entire letter to do your own posting, simply put your cursor at the beginning of this letter and click and hold down your mouse button. While continuing to hold down the mouse button, drag your cursor to the bottom of this document and over to just after the last character and release the mouse button. At this point the entire letter should be highlighted. Then, from the 'edit' pull down menu at the top of your screen select 'copy'. This will copy the entire letter into the computers memory. Step 2. Open a blank 'notepad' file and place your cursor at the top of the blank page. From the 'edit' pull down menu select 'paste'. This will paste a copy of the letter into notepad so that you can add your name to the list. Remember to eliminate the #1 position, move everyone up a spot (re-number everyone else’s positions) and add yourself in as #6. Step 3. Save your new notepad file as a .txt file. If you want to do your postings in different sittings, you'll always have this file to go back to. ----------------------------------- FOR NETSCAPE USERS: ----------------------------------- Step 4. Within the Netscape program, go to the pull-down window entitled 'Window' select 'NetscapeNews'. Then from the pull down menu 'Options', select 'Show all Newsgroups'. After a few moments a list of all the newsgroups on your server will show up. Click on any newsgroup you desire. From within this newsgroup, click on the 'TO NEWS' button, which should be in the top left corner of the newsgroups page. This will bring up a message box. Step 5. Fill in the Subject. This will be the header that everyone sees as they scroll through the list of postings in a particular group. Step 6. Highlight the entire contents of your .txt file and copy them using the same technique as before. Go back to the newsgroup 'TO NEWS' posting you are creating and paste the letter into the body of your posting. Step 7. Hit the 'Send' Button in the upper left corner. You're done with your first one! Congratulations... ---------------------------------------- INTERNET EXPLORER USERS: ---------------------------------------- Step 4. Go to newsgroups and select 'Post an Article'. Step 5. Fill in the subject. Step 6. Same as #6 above Step 7. Hit the 'Post' button. ---------------------------------------- THAT'S IT! All you have to do is jump to different newsgroups and post away, after you get the hang of it, it will take about 30 seconds for each newsgroup! **REMEMBER, THE MORE NEWSGROUPS YOU POST IN, THE MORE MONEY YOU WILL MAKE!! BUT YOU HAVE TO POST A MINIMUM OF 200** That's it! You will begin receiving money from around the world within day's! You may eventually want to rent a P.O. Box due to the large amount of mail you receive. If you wish to stay anonymous, you can invent a name to use, as long as the postman will deliver it. *JUST MAKE SURE ALL THE ADDRESSES ARE CORRECT.* Now the WHY part: Out of 200 postings, say I receive only 5 replies (a very low example). So then I made $5.00 with my name at #6 on the letter. Now, each of the 5 persons who just sent me $1.00 make the MINIMUM 200 postings, each with my name at #5 and only 5 persons respond to each of the original 5, that is another $25.00 for me. Now those 25 each make 200 MINIMUM posts with my name at #4 and only 5 replies each, I will bring in an additional $125.00! Now, those 125 persons turn around and post the MINIMUM 200 with my name at #3 and only receive 5 replies each, I will make an additional $626.00! OK, now here is the fun part, each of those 625 persons post a MINIMUM 200 letters with my name at #2 and they each only receive 5 replies, that just made me $3,125.00!!! Those 3,125 persons will all deliver this message to 200 newsgroups with my name at #1 and if still 5 persons per 200 newsgroups react, I will receive $15,625,00! With an original investment of only $6.00! AMAZING!..... And as I said, 5 responses is actually VERY LOW! Average is probably 20 to 30! So lets put those figures at just 15 responses per person Here is what you will make: at #6 $15.00 at #5 $225.00 at #4 $3,375.00 at #3 $50,625.00 at #2 $759,375.00 at #1 $11,390,625.00 When your name is no longer on the list, you just take the latest posting in the newsgroups and send out another $6.00 to names on the list, putting your name at number 6 again. And start posting again. The thing to remember is, that thousands of people all over the world are joining the Internet and reading these articles everyday, JUST LIKE YOU are now!! So can you afford $6.00 and see if it really works?? I think so... People have said, "what if the plan is played out and no one sends you the money ? So what! What are the chances of that happening when there are tons of new, honest users and new honest people who are joining the Internet and newsgroups everyday and are willing to give it a try? Estimates are at 20,000 to 50,000 new users, every day, with thousands of those joining the actual Internet. Remember, play FAIRLY and HONESTLY and this will work. **********You just have to be honest.********** Make sure you print this article out RIGHT NOW and also, try to keep a list of everyone that sends you money and always keep an eye on the newsgroups to make sure everyone is playing fairly. Remember, HONESTY IS THE BEST POLICY. You don't need to cheat the basic idea to make the money!! GOOD LUCK to all and please play fairly and reap the huge rewards from this, which is tons of extra CASH....By the way, I not only bought a new computer, I'm in the process of buying a computer company. Also remember, with your new found wealth, try to set up places for the needy and those that need caring and food and love..... Don't just buy cars and boats and houses and be greedy. This honestly and truly can make you independently wealthy.
Site Home Archive Home FAQ Home How to search the Archive How to Navigate the Archive
Compare FPGA features and resources
Threads starting:
Authors:A B C D E F G H I J K L M N O P Q R S T U V W X Y Z