embedded - confusion in implementing usb interface for programming cortex m3 -

embedded - confusion in implementing usb interface for programming cortex m3 -

i thinking of creating pcb nxp - lpc1756fbd80. has cortex m3 chip on it. want able programme chip on pcb using usb cable can straight connect laptop. im not sure if im doing right ive checked datasheet chip , has section on suggested usb interface solutions. section has circuit im not sure if plenty implement functionality want. inputs guys appreciated. give thanks

for new chip, need code through jtag port or chip's serial (uart) port & primary bootloader. "out of box", can't load new code on usb.

you need implement secondary bootloader runs after mcu's on-chip bootloader runs.

check out nxp's app note an10866 - "lpc 1700 secondary usb bootloader".

this text origin of app note:

a secondary bootloader piece of code allows user application code downloaded using alternative channels other standard uart0 used primary bootloader (on-chip). primary bootloader firmware resides in microcontroller’s boot rom block , executed on power-up , resets. after boot rom’s execution secondary bootloader executed. secondary bootloader in turn execute end-user application.

this application note uses usb illustration developing secondary bootloader on lpc1700 series microcontroller.

if sounds need (i believe is), congratulations. lpcware has files & info relevant topic.

embedded usb arm bootloader cortex-m3