56f82x_init.c

基于56F8346的异步电机VVVF控制程序。

/*
    56F82x_init.c



 	Metrowerks, a Motorola Company
 	sample code

 */


#include "56F82x_init.h"


extern _xROM_to_xRAM;
extern _pROM_to_xRAM;
extern _Xbss_length;
extern _start_bss;
extern _StackAddr;
extern _Ldata_size;
extern _Ldata_ROM_addr;
extern _Ldata_RAM_addr;


asm void init_56800_()
{
	bfset	#_32bit_compares,omr    // debugger will override this
	                                // if debugger option is on
	move	#-1,x0
	move	x0,m01                  // set the m reg to linear addressing

	move	hws,la                  // clear the hardware stack
	move	hws,la

// initialize compiler environment

CALLMAIN:

// setup stack
	move	#_StackAddr,r0	 // get stack start address
	nop
	move	r0,x:<mr15	 // set frame pointer to main stack top
	move	r0,sp		 // set stack pointer too
	move	#0,r1
	move	r1,x:(r0)

// xROM-to-xRAM utility
    move    #_xROM_to_xRAM,r0	 // check for option
    tstw    r0
    beq     end_rom2ram
    move    #_Ldata_size,y0      // set data size
    tstw    y0                   // LNE
    beq     end_rom2ram          // LNE if no init data, then exit
    cmp     #8191,Y0
    bls     do_xrom2xram
    debug			 // You have reached this because size of
			 	 // initialized data exceeded 2^13 size.
				 // Add code here to copy data above
                 // 2^13 (or 8191).
do_xrom2xram:
    move    #_Ldata_ROM_addr,r3  // src address -- xROM data start
    move    #_Ldata_RAM_addr,r1  // dest address -- xRAM data start
    do      y0,end_rom2ram       // copy for y0 times
    move    x:(r3)+,x0           // fetch value at address r3
    move    x0,x:(r1)+           // stash value at address r1
end_rom2ram:

// pROM-to-xRAM utility
    move    #_pROM_to_xRAM,r0    // check for the option
    tstw    r0
    beq     end_prom2xram        // if no pROM-to-xRAM, then exit
    move    #_Ldata_size,y0      // set data size
    tstw    y0                   // LNE
    beq     end_prom2xram        // LNE if no init data, then exit
    cmp     #8191,Y0
    bls     do_prom2xram
    debug			 // You have reached this because size of
				 // initialized data exceeded 2^13 size.
				 // Add code here to copy data above
                 // 2^13 (or 8191).
do_prom2xram:
    move    #_Ldata_ROM_addr,r3  // src address -- pROM data start
    move    #_Ldata_RAM_addr,r1  // dest address -- xRAM data start
    do      y0,end_prom2xram     // copy for y0 times
    move    p:(r3)+,x0           // fetch value at address r3
    move    x0,x:(r1)+           // stash value at address r1
end_prom2xram:

// clear bss always
    move    #0,x0                // set x0 to zero
    move    #_Xbss_length,y0     // set bss size
    tstw    y0                   // LNE
    beq     end_bss_clear        // LNE if no bss data, then exit
    cmp     #8191,Y0
    bls     do_bss_clear
    debug			 // You have reached this because size of
				 // uninitialized data exceeded 2^13 size.
				 // Add code here to clear bss data above
                 // 2^13 (or 8191).
do_bss_clear:
    move    #_start_bss,r1       // dest address -- bss data start
    do      y0,end_bss_clear     // do for y0 times
    move    x0,x:(r1)+           // stash zero at address
    nop
end_bss_clear:


// call main()

    jsr	 	main		 // call the users program
    debug
    rts
}