How can I boot in bootloader mode on chip of tm4c1294ncpdt?

Hello Nancy,

There is no default setting of the BOOTCFG register. You must program the BOOTCFG explicitly for boot configuration. Did you check with a debugger as to the value of the register.

Regards
Amit

Hi Amit,

 Thank a lot!

 default setting of the BOOTCFG register.---->I means that the chip registers factory setting.When we boot the chip in bootloader the first time,we van not modify the chip regster setting unless we compile and debug some program on the chip. But when we make our product degined with the ti-chip to mass-production,our board dosn't have the jtag interface just have uart and USB interface.So the way we try to load app code for the first timr is to set the chip to bootloader mode with uart or usb interface.  Then the trigger  way  to bootloader for the first time  is due to the factory setting of BOOTCFG. I dosn't understand how to set the chip to bootloader with the factory setting(when there is any user progrm in the chip).The factory setting for the trigger pin is which?How to enter the bootloader mode ?

Hello Nancy

When the flash is erased, then the ROM boot loader is automatically invoked. There is no requirement of BOOTCFG to have a valid setting. On an fresh part which has not application code, connect the USB to your PC. It should show a DFU class USB device in the Windows Device manager provided an external crystal is available.

Also it would be good if you can attach the schematic section of the TM4C1294NCPDT device on your board, to see if there are any obvious issue that shall prevent the ROM boot loader.

Regards
Amit

Hi Amit,

   Thank you for your kind reminder!

   I erase the entire flash(except the neccesary parts which can not be erase by user) with the  uniflash.Then my board(tm4c1294ncpdt) can boot into bootloader mode.I run  the LMFlash loader.Set the target to uart 0(with  the corresponding COM) and choose the blinky.bin file to program. The chip can be program in bootloader mode through uart0  interface.

  I understand that there is no more thing except  erase the flash to make the chip inito bootloader.I don't know what the PH7 held HIGH on the chip POR which can be seen from the  BOOTCFG register really means.

  When I buy a lot of  chips(tm4c1294ncpdt) from TI, I dosn't kown wheather the chips' flash are erased from factory setting.I use the Uniflash to earsse my entire flash,but the target can be craeted only when the debuggers are xds, stallials ICDI and so on.The uart0 can not be used as debuggers to run the uiniflash or in ccs.How can I find a way  to erase flash with uart?Or when the chip flash have some program in it,how can we boot the chip into bootloader？You know the chips are may be programmed when it is shipped to us. So the chips may be second programmed.