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| Issues programming NXP LPC11U34 |
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| iMo:
I have here an LPCXpresso board w/ 1343 on it. I split the board in half (removing the programmer) years back and used to use it as an mcu board only. I added 2 buttons, wired to Reset and USB_FToggle pin PIO0_1 (plus some resistors around). The USB_VBUS is pulled to GND via 3k3 here. While reading the 1343 datasheet: --- Quote ---USB_VBUS - A LOW level on this pin during reset starts the ISP command handler, a HIGH level starts the USB device enumeration. --- End quote --- I was using it with the built-in serial UART bootloader, it worked fine. I had to press the USB_FToggle button down and while hold it down I had to press/release the Reset button. --- Quote --- A LOW level during reset applied to the PIO0_1 pin is considered as an external hardware request to start the ISP command handler or the USB device enumeration. The state of PIO0_3 determines whether the UART or USB interface will be used (LPC1342/43 only). --- End quote --- Thus (except your 1k5+transistor D+ signaling) there are other 3 signals involved I had to handle properly - RESET, USB_FToggle and USB_VBUS. It could be you have to use the FlashMagic.exe to upload the binary via the UART. |
| Headless Chicken:
I am doing the same here, I have two buttons Reset and Bootloader, respectively on PIO0_0 and PIO0_1. I also have a jumper wire on PIO0_3, that I switch between GND and +3.3V. This part is working because when I power the device with the jumper on Vcc it pops up in windows (still as unrecognized usb), and on GND it does not. At least the USB stack is not starting. So I tried the procedure, press reset, press bootloader and keep it while releasing reset, wait a bit and release bootloader, and start programing. All with the PIO0_3 to ground, nothing. I actually already tried with both PIO and flashmagic, both fails but the led on the blackmagic does go blinky a bit. FlashMagic fails with a fail to autobaud. Interestingly enough hooking up the logic analyzer I see that the RX/TX stays to high. I don't believe I need a pullup/pulldown on these lines as well, or do I? |
| ehughes:
The bootloader is in ROM. I have several designs with it and it works without issue. Have you tried programming via SWD? It sounds like something is wrong in your physical layout. |
| iMo:
--- Quote ---So I tried the procedure, press reset, press bootloader and keep it while releasing reset, wait a bit and release bootloader, and start programing. All with the PIO0_3 to ground, nothing. --- End quote --- 1. press down USB_FToggle 2. press down Reset 3. release Reset 4. release USB_FToggle all with the PIO0_3 to ground for UART bootloader. --- Quote ---Interestingly enough hooking up the logic analyzer I see that the RX/TX stays to high. I don't believe I need a pullup/pulldown on these lines as well, or do I? --- End quote --- Rx and Tx are idle High, that is ok. You do not need pulldowns, you do need an FTxxx or similar usb/UART dongle. I always recommend to use 1k resistors (or similar value) in series with Rx and Tx wires for protection reasons. Board TX ----1k------UARTusbdongle RX Board RX ----1k-----UARTusbdongle TX Board GND-----------UARTusbdongle GND |
| Headless Chicken:
--- Quote from: ehughes on May 31, 2019, 07:00:30 pm ---It sounds like something is wrong in your physical layout. --- End quote --- And indeed something was ... |O One of the ground pin was floating. Solder that back and I get the USB as Mass storage. But now it is always booting in ISP mode, just to be sure I swapped the part, but it still only boots in ISP mode. I triple checked that PIO0_1 is to high, which it is, there is no glitch or anything, always at +3.3V. Looking at the boot process flowchart on page 396 of the documentation, it could be possible that the "user code valid" condition is failing. --- Quote from: imo on June 01, 2019, 10:05:20 am ---Rx and Tx are idle High, that is ok. --- End quote --- I mean they always stay high, and I'm not expecting them to stay high even when it is supposed to be flashing ;D I'm using the UART interface on the blackmagic probe, but I'm not sure how to tell it, or if it uses by default the UART interface. I'm gonna give it another try later on today with a binary from the NXP IDE just in case. |
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