Difference between revisions of "Microcontrollers-nxp"

Revision as of 19:39, 21 July 2022

parent topic Microcontrollers

2022

0721
• http://www.nxp.com/docs/en/application-note/AN2708.pdf intro to External Bus Interface EBI

Microcontrollers de NXP, starting with a NXP's Line Card:

2021-07-08

• http://www.nxp.com/docs/en/product-selector-guide/LPCMICROLNCD.pdf

And an article at Wikipedia:

• https://en.wikipedia.org/wiki/NXP_LPC

• https://www.nxp.com/docs/en/user-guide/UM10946-om13084_88.pdf

How to program dual-core microcontrollers:

• https://community.arm.com/developer/ip-products/processors/f/cortex-a-forum/4105/how-to-build-an-application-for-dual-core-m4-m0-mcu/18010

Not sure how useful this code example will be, it is posted in or around 2014. Hard to read on the NXP forum due to some funky formatting:

;/* File: example.s */

        .syntax unified             /* this makes the assembler automatically generate IT instructions for you */

        .cpu    cortex-m0           /* this selects the cortex-m0 architecture and helps you avoid using cortex-m3/cortex-m4 instructions */

        .text                       /* this makes sure the code goes into the .text section */

        .global m0vectors

        .word   0x20004000          /* this defines the initial stack pointer for the Cortex-M0 */

        .word   m0reset             /* the reset exception vector */

/* here you should place your other exception vectors. There are too many to include in this example */

        .global m0test              /* this exports the symbol m0test, so you can reference it from for instance C */

        .func   m0test,m0test       /* this names the symbol m0test as a function (for the debug-info) */

        .type   m0test,%function    /* this tells the assembler (and linker) what kind of symbol we're generating */

        .thumb_func                 /* this is necessary if pointers use the symbol */

        .align                      /* this makes sure the code is positioned on a 16-bit boundary */

m0test:                             /* this defines the actual symbol */

        ldr     r0,=0x01234567      /* example code, load a value into r0 */

        bx      lr                  /* return to the calling function */

m0reset:

        bl      m0test              /* this is the startup-code, call our function */

lockup: wfi                         /* sleep the CPU; it'll wake up if an interrupt occurs */

         b       lockup              /* go back to sleep */

        .size   m0test, . - m0test  /* this tells the linker how big this function is, so it can correctly exclude it if it's unused */

        .endfunc                    /* this marks the end of the function (for the debug-info) */

You can then refer to the code from your C file...

/* File: main.c */

#include <ipc_queue.h>

/* Note: you don't need argc and argv on a microcontroller. */

int main(int argc, const char *argv[])

{

     IPC_haltSlave();

     SET_SLAVE_SHADOWREG(m0vectors);

     IPC_startSlave();

     while(1)

     {

          asm volatile("wfi");

     }

     return(0);

}