最近用的是PIC24FJ64GA002, 能做很多好玩的东西。。先把最近算作helloworld的东西放上来好了。
这个code实现的功能是，按一个键，然后里面生成一个随机数，LSB 8bits输出到LED。 分别用汇编和C写了两遍，一共两个Lab。一开始以为比较容易实现的，但是debug的时候遇到了不少问题。
1.BoilerPlate一定要写进去，第二次用c写的时候，和lab partner 搞了好久，只有6个led是对的的，7 8 怎么都不显示，最后发现是没放BP 2.要考虑debounce和release press time，每次按下去之后，应该有code等用户release button 3.多看reference manual，比datasheet好
其实code写的有点不规范，没有做优化，凑合着看怎么实现的就好。。 .equ __P24FJ64GA002,1 .include "p24Fxxxx.inc" #include "xc.inc" config __CONFIG2, POSCMOD_EC & I2C1SEL_SEC & IOL1WAY_OFF & OSCIOFNC_ON & FCKSM_CSECME & FNOSC_FRCPLL & SOSCSEL_LPSOSC & WUTSEL_FST & IESO_OFF config __CONFIG1, WDTPS_PS1 & FWPSA_PR32 & WINDIS_OFF & FWDTEN_OFF & COE_ON & BKBUG_ON & GWRP_ON & GCP_ON & JTAGEN_OFF .bss c: .space 2 ;a 16 bits variables x: .space 8 ;a 64 bits variables a: .space 8 ;a 64 bits variables stack: .space 32 ;this will be our stack area .text .global _main cleanmem: ;clean memory from 0x900 to 0x91E push w0 push w2 mov #0x0000, w0 mov #0x900, w2 mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] mov W0, [w2++] pop w2 pop w0 return memsetup: ;test file!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! mov #0x0002, w3 mov #0x0004, w2 mov #0x0003, w1 mov #0x0008, w6 mov #0x0005, w5 mov #0x0009, w4 return peri_initilize: ;initilize peri setting and variables push w0 ;protect working register value push w1 mov #0xffff,w0 mov w0,LATB mov #0x0003, w0 mov w0, TRISB ;make RB 2-9 are output mov #0x9fff,w0 mov w0,AD1PCFG ;make PORTB all digital mov #0xFFFF, w0 mov w0, TRISA ;all RA as input bset CNPU1, #2 ;turns on internal pull up on CN01 (RA0) pop w1 pop w0 return vari_initilize: ;initilize all values x,a,c push w1 ;protect stack push w2 push w3 mov #0x0,w3 ;initilize x mov #0x1,w2 mov #0x330e,w1 mov w1,x mov w2,x+2 mov w3,x+4 mov #0x5,w3 ;initilize a mov #0xDEEC,w2 mov #0xE66D,w1 mov w1,a mov w2,a+2 mov w3,a+4 mov #11,w1 ;initilize c mov w1,c pop w3 pop w2 pop w1 return mult_48_bit: ;w3:w2:w1 * w6:w5:w4,, result=w9:w8 final result will be store in 0x900-0x91E push w8 push w9 push w7 mov #0x0000, w8 mov #0x0000, w9 mov #0x900, w7 btst.c [w7],#0x1 mul.uu w1, w4, w8 ; we divide mul in three steps addc w8, [w7], [w7++] addc w9, [w7], [w7] mul.uu w4,w2,w8 addc w8, [w7], [w7++] addc w9, [w7], [w7] mul.uu w4,w3,w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mov #0x902, w7 mul.uu w1, w5, w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mul.uu w5,w2,w8 addc w8,[w7], [w7++] addc w9, [w7],[w7] mul.uu w5,w3,w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mov #0x904, w7 mul.uu w1, w6, w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mul.uu w6,w2,w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mul.uu w6,w3,w8 addc w8,[w7], [w7++] addc w9,[w7], [w7] mov #0x900,w0 mov #0xb,w1 add w1,[w0],[w0] mov #0x900, w7 mov [w7],w8 mov w8, x mov #0x902, w7 mov [w7],w8 mov w8, x+2 mov #0x904, w7 mov [w7],w8 mov w8, x+4 pop w7 pop w9 pop w8 return rand48generator: mov #0x0005, w3 ;a mov #0xDEEC, w2 mov #0xE66D, w1 mov #0x0000, w6 ;X first mov #0x0001, w5 mov #0x330E, w4 call mult_48_bit return ;mov 0x800, w0 ;mov #0x000B, w1 ;add w1, [w0], [w0] msec: ;this isn't where we start - it's a subroutine push w1 ;save WREG1 mov #14000,w1 msloop: sub #1,w1 bra NZ,msloop nop pop w1 ;restore WREG1 return ; msecs does nothing for W0 milliseconds msecs: ;another subroutine push w0 ;save WREG0 mssloop: sub #1,w0 bra N,mssdone call msec bra mssloop mssdone: pop w0 ;restore WREG0 return makenextx: mov x+4,w6 mov x+2,w5 mov x,w4 mov a+4,w3 mov a+2,w2 mov a,w1 call mult_48_bit return loop: call msec ;we wanna check user input with a delay of 40ms to prevent debouncing btss PORTA,#0 bra loop call makenextx call cleanmem mov x, w0 sl w0,#2,w0 mov w0,PORTB call msec bra loop usefull_loop: call rand48generator _main: call cleanmem call peri_initilize call vari_initilize bra loop goto $ .end