We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hello again,
I need an 8051 variant which can handle USB2.0 (Full or High-Speed) and has a full 16-bit external address space (w/ data-bus of course): I shall be bank-switching for a 2Mx8 storage area.
I don't mind splitting the design into a small (very small USB to UART) mated to a high-pin-count 8051 flavored IC. Naturally power-consumption is a huge issue: LOW POWER.
I was going to use ST-Microelectronics uPSD3454x but they are discontinuing it. Now I must convert the design over to a [production] part.
I concidered using Actel's FPGA with embedded Core8051 or Cortex M-1, but the demanding qualities of the project prohibit that avenue at this time.
I've been looking at SilLabs, yet many of the bells-n-whistles aren't needed.
Requirement 1.0 --------------- Low Power--Battery Operated with USB charge capability
Requirement 1.0.1 ----------------- Sleep Mode, and Power-down mode (wake-up on NMI)
Requirement 1.0.2 ----------------- Capable of data-logging for 24+ hours at 'full operation'
Requirement 1.1 --------------- Needs to address up to (and maybe more than) 2Mx8 external low-power RAM
Requirement 1.2 --------------- USB is the primary mode of PC\device communication. Requirement 1.2.1 ----------------- USB 1.1 would suffice for such low content (2Mx8)
Requirement 1.3 --------------- Capable of interfacing to an FPGA for dual User Graphics 162 x 96 [each] engine
A low-power ARM [Cortex] would be a possibility, but I think it is over-kill.
Q1) What is a high-pin count, low-power 8051 with Flash (64k would be nice)? Q2) What is the smallest and lowest power USB to UART device.
I figured that erik, per, Andy, and Tamir might have a quick answer... and not the Keil parametric search.
Sincerely,
--Cpt. Vince Foster 2nd Cannon Place Fort Marcy Park, VA
Hey Capt; Sounds like another fun project. I used the SiLabs F340 as the USB engine for legacy reasons. The client had lots of software running and a pretty good USB interface. The F340 has the ability to present a 16 bit address non-multiplexed but still only an 8 bit data path.
We had lots of high speed FPGA fabric to create our pattern generator outputs. I interfaced the F340 16 bit address lines to Block Ram on the Xilinx FPGA. The four LSB address lines selected one of four bytes of Block Ram. I use only 32 bits but the Xilinx IP for the external interfaced Block Ram demands the full four bits as the minimum.
I used additional FPGA GPIO as my port expander for GPIO not supported by the F340. My need to write pattern data from the USB via the F340 is not super fast but I created two Block Ram storage areas in the FPGA and ping/pong the data from the F340 to the FPGA. I can change an output pattern on the fly with no loss of resolution.
I still suggest that you look at the Stellaris devices. For low current, low cost and big bit crunching, you can't beat some of the Stallaris chips.
A typical Stallaris LM3Sxx starts at $2.70 US in qty of 1! No USB on that chip but there other chips with more RAM/Flash, USB OTG and Device at Full Speed. Cost run under $10.00 in small qtys. Also, Stellaris supports their chips with a lot of good code examples free of charge.
Why did I not implement USB on the FPGA?? Cost of the USB IP core was a lot more than mounting the F340 plus the legacy code issue.
Good luck and keep us posted on your project. Bradford
Capt; I just remembered another simple project. I used the low cost Stellaris interfaced to a SiLabs CM2400 LCD driver. Worked great for a low cost non-critical project. Bradford
I'd just like to add emphasis to that:
Stellaris supports their chips with a lot of good code examples free of charge.
It is a sad fact that a great deal of the free examples provided by all too many suppliers are very bad - see rant here: www.8052.com/.../174319
I think the Stellaris examples are not only good examples for (potential) customers trying to use their chips - they should also be studied by other manufacturers as examples of how to write example code!
I shall take a peek at the Stellaris parts. Thanks for the suggestion. IF Andy seconded the part's support, then it must be worth checking into.
Sounds like you had some fun with that project. I do plan on having fun with mine... even though it is intended for the commercial market (headaches).
Thanks again guys.
Also, I'd like to mention that it is a home project, so I have to fight for time between the wife and kids. I used Protel DXP at home while Altium Designer here at work. (Yes, I have the full-blown Keil ARM/C51 at home, and 'soon' I'll have it here at work. I just need to complete the schematics and PWB first).
I can't mix the two projects, although the IP rolling around in my head may bleed over into one another.
At work, I'm using Ti DSPs, and ARM Cortex M-3, Actel ProASIC3E, and possibly a Xilinx part (I'm not fond of Xilinx though).
The home prototype is a proof of concept, so although I touted low-power, I must be able to prove a migration path to 'lowest power' for some Venture Capitol monies. (which, due to the Obambi Economy is rather hard to come by).