Hi,
I order OM13066 board, which is LPC11U24 evaluation board. I want to program LPC11U24 through USB interface, so I isolate this board target side, and provide the independent power for LPC11U24. I also follow UM10462 and reference one post in this community.
"Content originally posted in LPCWare by DiligentMinds.com on Thu Aug 30 10:32:12 MST 2012
Just for you-- I just tested it. I am using the 48-pin (Rev-B) version of your device, but otherwise they are the same. Yes-- USB_CONNECT (P0.6) goes low if you enable the ISP by holding (P0.1) low during a reset. Note that, to enter the USB ISP, "VBUS" must also be connected to P0.3, and it must be high when reset happens (and P0.1 is low).
On my device, if I leave the batteries out, it is powered by the USB host when I plug it in (through a 3V3 regulator of course). In this case, when I hold P0.1 low, and plug in the USB cable, it DOES NOT enter the ISP (as I would expect)-- I have to further cause a reset-- and THEN it goes into the USB ISP. I'm guessing that this is because the power is not ready (or something) when the (internal) reset goes high... Another deviation from the ap-note is that I put a 10K resistor in series with VBUS to P0.3-- I know the data-sheet says that this pin is "5V tolerant", but I wanted to limit the current into the pin anyway, just to be safe...
I used the same circuit for the 1.5K pull-up through a P-channel FET as was given in the ap-notes, and it appears to work fine. (P0.6 goes low, driving the drain of the PFET high, which pulls up the 1.5K resistor on the D+ line of the USB cable).
This is used by the ISP, and if you are programming a USB device, it allows your software to do a "soft connect"-- ie., it's like unplugging the USB cable from the host, and then re-plugging it back in to re-enumerate the USB device. This might be done if you (for some reason) have re-configured your USB device, and you want the host to treat it in a different way.
So, you probably do need this pull-up PFET (or PNP) arrangement if you are going to use the USB port for either USB ISP or for a USB device.
I hope this helps!
--Ken Peek
I can see "CRP DISABLED" drive displayed on my PC, and I also see one bin file which is "firmware.bin" , and its date is 2/6/2009. I delete this file and drag my own bin file. After reset the board by shorting PIO0_0 to ground, unplug PIO0_1 from ground and unplug PIO)_3 from 3.3V, the board is still not working. When I re-check the "CRP DISABLE" drive, the file I loaded in is disappeared, and old file "firmware.bin" is back, so I'm wondering which step is wrong. By the way, I also padded my own file to 32kB, because document an11305 indicates
"Using a padded (128 kB or flash size) programming file also provides a means for
the programming tool to error-check that the correct LPC part is connected (by
comparing file sizes of the new firmware and the firmware.bin on the device) without
additional configuration information"
the padded files is still not working. Is there any NXP technical engineer I can call in to talk?
Thanks,
Frank