I am developing an elevator GLCD display (128*64) with LPC2148 Micro controller, I have done program and PCB designing also. Now I want to upload the program to micro controller, how to do it? Before fixing micro controller or after fixing micro controller want to upload program?
If I understand correctly you want to program the device without using a bootloader or a JTAG. There is some standalone programmers available for the LPC2148 device. Example here. This will allow the MCU to be programmed before placing it on the board.
The maintainability of your design however raises red flags. You should at least have a JTAG header on the board even if it is not populated. JTAG is very flexible and cheap and add lots of development and testing options.
If I am right, than the LPC2100 series does have an ROM bootloader. You only have to pull a pin (I think P0.14) to ground while reset.
Flashmagic would than be a tool of choice to download the program.
Pro: No additional hardware needed.
Con: The bootloader pin and USART (normally USART0) need to be accessable.
1.Use the Keil compiler to compile your code and
generate hex file
2.Download and Install Flash Utility
3.In flash utility
Select Com port ,Board, Baud rate (may be default) and file
4.Now click on Upload to flash
Related
I am currently using Xilinx ZCU106 board, and I am curious about How does JTAG support flash memory programming. I can upload the boot images or hardware logic just by connecting JTAG USB cable to USB connector at the ZCU106 Board, and press the flash button on the host PC. By doing this it looks like the QSPI Flash holds the boot images or hardware logic image and the system initializes itself by using this image. It seems like a magic, and I want to know about the detail.
So far I understood is that I can access JTAG interface via USB cable (thanks to the FTDI chip?), and JTAG boundary-scans the devices connected to it.
However the problem is here, I couldn't find the link between JTAG and QSPI Flash (MT25QU512ABB8ESF-0SIT). I searched several references, including manual of QSPI Flash (MT25QU512ABB8ESF-0SIT, https://media-www.micron.com/-/media/client/global/documents/products/data-sheet/nor-flash/serial-nor/mt25q/die-rev-b/mt25q_qlkt_u_512_abb_0.pdf) but there seems no port for JTAG (such as TDI, TDO, and TCK), but only SPI.
So the first assumption, I thought on the JTAG chain maybe there is a SPI controller to flash the memory. However I couldn't find any clue on the references that I've read so far that a SPI controller exists on the chain or even a SPI controller that controls the QSPI flash really exists. And the second assumption, I thought PS- ARM Cortex A53- TAP (?) does the magic. PS TAP receives JTAG signal and processes the JTAG command. To be precise, let's say about flash memory programming case, then there is like a JTAG command for write data on the flash memory via SPI.
Among these two, I wonder if there is the answer. One thing for the last, if the second one suppose to be the answer, then the processor (Cortex A53) should implement the functionalities by hardware logic to parse Flash write/erase command signal from JTAG interface and let the SPI controller that the system includes perform the write/erase job? Somewhere I read that the JTAG itself supports writing data on the Flash memory but everything I could find was just TDI, TCK, TDO, TMS, and TRST ports which does not fit in any port of QSPI Flash.
Probably I am confusing a lot of concepts very much, but I want to know about the exact mechanism behind the scene on JTAG flash memory programming.
Normally, it will do with the following sequence:
Send some software to target processor in RAM
Send data to target processor (in RAM)
Trigger execute command to store data into the flash memory.
Now the expected data are available in flash memory.
Why would the file system (CIRCUITPY) of an Adafruit board running CircuitPython not show up when connecting it to a suitable host via a micro usb cable?
This happens to me often, usually when I am copying files via Windows, most often with my trinket which uses the integrated chip flash memory rather than the separate SPI flash chip. Why? I don't know. A bug somewhere obviously. :)
So the solution.
Always save your work files locally or use a source code solution like git
Switch to the boot mode (double click reset)
Drag the erase.uf2 file to clear the flash memory
Drag the circuit python uf2 file to reflash python
Restore your files saved on your PC
Basically, I've made it a habit to assume the flash memory is temporary and volatile and not store any critical code only there.
You can read more about the erase uf2 and reflashing, general troubleshooting here:
https://learn.adafruit.com/welcome-to-circuitpython/troubleshooting
Besides your first answer about the cable, because of the relatively inexpensive nature of the boards and direct access to their power/ground sometimes the EPROMs that the file system are hosted on just go bad and give unexpected results. Best idea is to:
Test your environment with another board.
Reflash micro python on your board so you can start from scratch (didn't mention if you'd tried that).
JerryN mentioned the most common cause of this is using a USB cable with no data wires. Some USB cables are designed for power-only and have 2 rather than 4 conductors. These will power the device but will prevent mounting of the drive and use of the serial connection over USB.
Unfortunately these cables are often not marked as power-only so can be difficult to spot.
Another case is where CPLAYBOOT (this varies per board, e.g. GEMMABOOT, FEATHERBOOT, TRINKETBOOT) disappears on Windows. This can be caused by installation of the Arduino software which has an old, conflicting driver from 2007. More information on Adafruit: Circuit Playground Express: Troubleshooting.
A very rare case is a mis-seated USB connector. In my case the power was ok but the data wasn't for a good quality cable which had previously worked fine. Unplugging the USB cable at the host end and re-inserting it solved the problem.
the atmega microcontrollers have the internal programmable memory.So the usb flash device write data to internal memory of atmega through spi or it store the program and works as slave?i also want to know can the atmega get program,file in the MicroSD and run without internal memory or it need to run a program in internal disk then including the program in MicroSD?i don't know how the process work in atmega microcontroller.
There are several ways to program the AVR:
Using an external programmer. The Chip is in reset state during this. Then the programmer uses special a special protocol to directly write to the flash inside the controller. This is how your USB programming device probably writes code to the AVR. There are several protocols for this, but the most common one uses the same pins that are used by SPI. You should not confuse them just because of that ;-).
The controller writes the program itself. The chip is actively executing a program. That program on the chip fetches the instructions from e.g. a sd card and using the SPM instruction to copy it to local flash.
The AVR can only fetch instructions from it's own flash memory - you cannot execute directly from RAM or from any other external source.
The best answer for this question you can find at the end or middle of datasheet for AVR device (eg ATMEGA 328P-PU). If you are using some flashing device connected with computer, there is some initialization sequence after start and then there are send some 4 Bytes commands that tels microcontrolers, where to store values to flash and/or eeprom, fuse bits, or cares about erasing etc. There is also posible to read ID of chip.
Atmega microcontroler can be also programmed in paralel mode, where are some bits used for sending commands that tels, what to do with data on data bit.
If you ask about downloading program from SD card or any other device, there is possible to write to the flash through SPM, as there was told above. Some devices do not have part of flash for downloader - if I remember ATMEGA 48, and devices, that have configurable part of memory usable also for downloader, that can handle this, eg. ATMEGA 88, 168, 328. So if you want to download program from SPI, USART, TWI, etc, you need to configure fuse bits and create downloader that will do it for you. I am not sure, how ATMEGA 48 do this, but there si probably possible to write whole flash by SPM instruction.
However the best answer you can find in the datasheet. On pages folowing 255 you can find further information. http://www.atmel.com/images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet_Complete.pdf
I am working with a simple PIC18F2550 and I'm wondering about how to get a bootloader working on it. It's a very simple device with a USB port and CDC firmware. When I download Tiny Bootloader onto the pic, my PC doesn't recognize the device. Do I NEED to have a USB controller in my circuit in order for it to work? Such as the MAX232?
Would the same apply to the PIC32MX795F512L?
Thanks!
It is clear from the Tiny PIC boot loader documentation that it expects a UART connection rather than USB (that is what the MAX232 is for - it is an RS232 line driver).
You could simply do that and use an external serial to USB converter thus saving the code space required by the USB-CDC stack. Otherwise you will have to modify the boot loader code to use the CDC driver rather than the UART.
You will have to link the USB code with the boot loader, which will no doubt significantly increase its size. You may need therefore also to move the application start address to accommodate the boot loader. Furthermore, if the application needs USB comms, you may need a separate copy of the code in the application unless you provide a method of accessing the bootloader code from the application; which is possible, but not necessarily straightforward.
All that said, note the part at the end of the end of the page about extending the bootloader; On the face of it it seems unsuited to extension. Without looking at the code and its memory map, it is not clear why it has this constraint.
The PIC18F2550 has a USB interface built into it. It is called the "USB SIE" and there is a large section in the datasheet that documents it. If you make the right electrical connections, you should be able to connect your PIC18F2550 directly to a USB port without any active electronics between them. There is no reason you would need extra USB hardware just because you want to run a bootloader.
If you want to troubleshoot your problems with the bootloader, you should probably post another question with more details. It could be a problem with the PIC's configuration bits or something like that. I recommend trying to modify the bootloader to get it to blink an LED as a basic first step just so you can verify that you were able to get its code to run at all.
Does anyone know of a good learning resource for building your own bootloader for an embedded system? From reading various textbooks, I have a good overview of what a bootloader is supposed to do, and some textbooks include snippets of assembler to show how the bootloader should be built.
However, when I search for resources/tutorials that describe how to build a bootloader, everything I've found so far is either too advanced, (assuming a knowledge of certain preliminaries and are thus hard to follow), or, they are dealing with creating a bootloader for a pc or an emulator. Ideally I'm looking for a single resource/book, that covers preliminaries, and walks me through the process. I'm happy to purchase a particular chip, and relevant cables, if the tutorial/textbook requires that.
The term bootloader is quite broad, so does your quest have roots in a few dozen lines of code with a serial bootloader or are you interested in a linux type full blown operating system (uboot) that has gobs of features and drivers and stacks?
If you dont already know that answer or dont know what I am talking about you need to figure that out, I would start small...even if you desire the huge monster operating system solution, you should start with bare metal (which is what a bootloader is, a bare metal program) chip comes out of reset, your code runs first, blinks an led. Then control the rate of the blinking led, then if you have a push button read the push button and make it change the led (demonstrating input and output). Then find and use a timer to blink the led if you didnt already (use polling first please, interrupts later). Now you can do clock math and have an idea how the chips clock tree is so use that to get a uart up, tx only first, then rx/tx echo what your receive. THEN you are ready to talk about your first bootloader, which should involve some serial protocol (invent your own or use xmodem or something) that actually "boots" and then lets you "load" other programs after booting.
You can do all of this (well virtual leds in some other form) using simulators, and that may not be a bad idea since the hard part of bare metal is first off controlling the assembler compiler and linker to make a binary that actually boots up and runs. Then piles of sub $10 and sub $20 boards that you can learn to write a bootloader for (msp430 launchpads, the other launchpads, stm32f0 and f4 discovery boards, the raspberry pi, probably not the beagles avoid those for now, oh and a myriad of avr based boards, avoid x86 start with microcontrollers, arm, avr, msp430).