写个8点FFT程序玩

 @ stm32f030f4p6 asm

        @fft 256点

        @2018-01-06

         .thumb                 

         .syntax unified

.section .data        

               .equ STACKINIT,                 0x20001000

        .equ xuanzhuanyinzi,                0x20000804

        .align 4

shuru:

        .int 0,4539,-1374,3185,-5935,1471,2148,1201,3899,-5842,2413,-498,3925,3547,-4170,2482,-2634,6066,2481,-1268,1639,-3687,6998,1237,2166,172,-3437,6391,343,5275,-1388,-2063,4328,137,7282,-2446,-67,1298,658,7704,-2537,1890,-1933,1635,6484,-1493,3207,-4536,2591,3991,477,3517,-5847,3008,906,2841,2796,-5562,2521,-1981,4878,1351,-3818,1059,-3999,5901,-294,-1155,-1107,-4777,5468,-1583,1648,-3430,-4326,3532,-2114,3796,-5243,-3012,470,-1770,4706,-5970,-1409,-3003,-761,4167,-5308,-108,-6030,454,2389,-3347,478,-7847,1328,-70,-555,241,-7998,1414,-2490,2336,-605,-6463,534,-4194,4544,-1611,-3655,-1145,-4756,5457,-2255,-305,-3141,-4107,4818,-2136,2751,-4798,-2540,2808,-1120,4811,-5487,-596,0,596,5487,-4811,1120,-2808,2540,4798,-2751,2136,-4818,4107,3141,305,2255,-5457,4756,1144,3655,1611,-4544,4194,-534,6463,605,-2336,2490,-1414,7998,-241,555,70,-1328,7847,-478,3347,-2389,-454,6030,108,5308,-4167,761,3003,1409,5969,-4706,1770,-470,3012,5243,-3796,2114,-3532,4326,3429,-1648,1583,-5468,4777,1106,1155,294,-5901,4000,-1059,3818,-1351,-4878,1981,-2521,5562,-2796,-2841,-906,-3008,5847,-3517,-477,-3991,-2591,4536,-3207,1493,-6484,-1635,1933,-1890,2537,-7704,-658,-1298,67,2446,-7282,-137,-4328,2063,1388,-5275,-343,-6391,3437,-172,-2166,-1237,-6998,3687,-1639,1268,-2481,-6066,2634,-2482,4170,-3547,-3925,498,-2413,5842,-3899,-1201,-2148,-1471,5934,-3185,1374,-4539

        

hudieweifanzhuan:

        .int 0x0000,0x0200,0x0100,0x0300,0x0080,0x0280,0x0180,0x0380,0x0040,0x0240,0x0140,0x0340,0x00C0,0x02C0,0x01C0,0x03C0,0x0020,0x0220,0x0120,0x0320,0x00A0,0x02A0,0x01A0,0x03A0,0x0060,0x0260,0x0160,0x0360,0x00E0,0x02E0,0x01E0,0x03E0,0x0010,0x0210,0x0110,0x0310,0x0090,0x0290,0x0190,0x0390,0x0050,0x0250,0x0150,0x0350,0x00D0,0x02D0,0x01D0,0x03D0,0x0030,0x0230,0x0130,0x0330,0x00B0,0x02B0,0x01B0,0x03B0,0x0070,0x0270,0x0170,0x0370,0x00F0,0x02F0,0x01F0,0x03F0,0x0008,0x0208,0x0108,0x0308,0x0088,0x0288,0x0188,0x0388,0x0048,0x0248,0x0148,0x0348,0x00C8,0x02C8,0x01C8,0x03C8,0x0028,0x0228,0x0128,0x0328,0x00A8,0x02A8,0x01A8,0x03A8,0x0068,0x0268,0x0168,0x0368,0x00E8,0x02E8,0x01E8,0x03E8,0x0018,0x0218,0x0118,0x0318,0x0098,0x0298,0x0198,0x0398,0x0058,0x0258,0x0158,0x0358,0x00D8,0x02D8,0x01D8,0x03D8,0x0038,0x0238,0x0138,0x0338,0x00B8,0x02B8,0x01B8,0x03B8,0x0078,0x0278,0x0178,0x0378,0x00F8,0x02F8,0x01F8,0x03F8,0x0004,0x0204,0x0104,0x0304,0x0084,0x0284,0x0184,0x0384,0x0044,0x0244,0x0144,0x0344,0x00C4,0x02C4,0x01C4,0x03C4,0x0024,0x0224,0x0124,0x0324,0x00A4,0x02A4,0x01A4,0x03A4,0x0064,0x0264,0x0164,0x0364,0x00E4,0x02E4,0x01E4,0x03E4,0x0014,0x0214,0x0114,0x0314,0x0094,0x0294,0x0194,0x0394,0x0054,0x0254,0x0154,0x0354,0x00D4,0x02D4,0x01D4,0x03D4,0x0034,0x0234,0x0134,0x0334,0x00B4,0x02B4,0x01B4,0x03B4,0x0074,0x0274,0x0174,0x0374,0x00F4,0x02F4,0x01F4,0x03F4,0x000C,0x020C,0x010C,0x030C,0x008C,0x028C,0x018C,0x038C,0x004C,0x024C,0x014C,0x034C,0x00CC,0x02CC,0x01CC,0x03CC,0x002C,0x022C,0x012C,0x032C,0x00AC,0x02AC,0x01AC,0x03AC,0x006C,0x026C,0x016C,0x036C,0x00EC,0x02EC,0x01EC,0x03EC,0x001C,0x021C,0x011C,0x031C,0x009C,0x029C,0x019C,0x039C,0x005C,0x025C,0x015C,0x035C,0x00DC,0x02DC,0x01DC,0x03DC,0x003C,0x023C,0x013C,0x033C,0x00BC,0x02BC,0x01BC,0x03BC,0x007C,0x027C,0x017C,0x037C,0x00FC,0x02FC,0x01FC,0x03FC

        

fft3xuanzhuanyinzi:

        .int 0x8000,0x0000,0x5A82,0xFFFFA57E,0x0000,0xFFFF8000,0xFFFFA57E,0xFFFFA57E

fft4xuanzhuanyinzi:

        .int 0x8000,0x0000,0x7641,0xFFFFCF05,0x5A82,0xFFFFA57E,0x30FB,0xFFFF89BF,0x0000,0xFFFF8000,0xFFFFCF05,0xFFFF89BF,0xFFFFA57E,0xFFFFA57E,0xFFFF89BF,0xFFFFCF05

fft5xuanzhuanyinzi:

        .int 0x8000,0x0000,0x7D8A,0xFFFFE708,0x7641,0xFFFFCF05,0x6A6D,0xFFFFB8E4,0x5A82,0xFFFFA57E,0x471C,0xFFFF9593,0x30FB,0xFFFF89BF,0x18F8,0xFFFF8276,0x0000,0xFFFF8000,0xFFFFE708,0xFFFF8276,0xFFFFCF05,0xFFFF89BF,0xFFFFB8E4,0xFFFF9593,0xFFFFA57E,0xFFFFA57E,0xFFFF9593,0xFFFFB8E4,0xFFFF89BF,0xFFFFCF05,0xFFFF8276,0xFFFFE708

fft6xuanzhuanyinzi:

        .int 0x8000,0x0000,0x7F62,0xFFFFF375,0x7D8A,0xFFFFE708,0x7A7D,0xFFFFDAD8,0x7641,0xFFFFCF05,0x70E2,0xFFFFC3AA,0x6A6D,0xFFFFB8E4,0x62F2,0xFFFFAECD,0x5A82,0xFFFFA57E,0x5133,0xFFFF9D0E,0x471C,0xFFFF9593,0x3C56,0xFFFF8F1E,0x30FB,0xFFFF89BF,0x2528,0xFFFF8583,0x18F8,0xFFFF8276,0x0C8B,0xFFFF809E,0x0000,0xFFFF8000,0xFFFFF375,0xFFFF809E,0xFFFFE708,0xFFFF8276,0xFFFFDAD8,0xFFFF8583,0xFFFFCF05,0xFFFF89BF,0xFFFFC3AA,0xFFFF8F1E,0xFFFFB8E4,0xFFFF9593,0xFFFFAECD,0xFFFF9D0E,0xFFFFA57E,0xFFFFA57E,0xFFFF9D0E,0xFFFFAECD,0xFFFF9593,0xFFFFB8E4,0xFFFF8F1E,0xFFFFC3AA,0xFFFF89BF,0xFFFFCF05,0xFFFF8583,0xFFFFDAD8,0xFFFF8276,0xFFFFE708,0xFFFF809E,0xFFFFF375

fft7xuanzhuanyinzi:

        .int 0x8000,0x0000,0x7FD8,0xFFFFF9B9,0x7F62,0xFFFFF375,0x7E9D,0xFFFFED38,0x7D8A,0xFFFFE708,0x7C29,0xFFFFE0E7,0x7A7D,0xFFFFDAD8,0x7884,0xFFFFD4E1,0x7641,0xFFFFCF05,0x73B5,0xFFFFC946,0x70E2,0xFFFFC3AA,0x6DCA,0xFFFFBE32,0x6A6D,0xFFFFB8E4,0x66CF,0xFFFFB3C1,0x62F2,0xFFFFAECD,0x5ED7,0xFFFFAA0B,0x5A82,0xFFFFA57E,0x55F5,0xFFFFA129,0x5133,0xFFFF9D0E,0x4C3F,0xFFFF9931,0x471C,0xFFFF9593,0x41CE,0xFFFF9236,0x3C56,0xFFFF8F1E,0x36BA,0xFFFF8C4B,0x30FB,0xFFFF89BF,0x2B1F,0xFFFF877C,0x2528,0xFFFF8583,0x1F19,0xFFFF83D7,0x18F8,0xFFFF8276,0x12C8,0xFFFF8163,0x0C8B,0xFFFF809E,0x0647,0xFFFF8028,0x0000,0xFFFF8000,0xFFFFF9B9,0xFFFF8028,0xFFFFF375,0xFFFF809E,0xFFFFED38,0xFFFF8163,0xFFFFE708,0xFFFF8276,0xFFFFE0E7,0xFFFF83D7,0xFFFFDAD8,0xFFFF8583,0xFFFFD4E1,0xFFFF877C,0xFFFFCF05,0xFFFF89BF,0xFFFFC946,0xFFFF8C4B,0xFFFFC3AA,0xFFFF8F1E,0xFFFFBE32,0xFFFF9236,0xFFFFB8E4,0xFFFF9593,0xFFFFB3C1,0xFFFF9931,0xFFFFAECD,0xFFFF9D0E,0xFFFFAA0B,0xFFFFA129,0xFFFFA57E,0xFFFFA57E,0xFFFFA129,0xFFFFAA0B,0xFFFF9D0E,0xFFFFAECD,0xFFFF9931,0xFFFFB3C1,0xFFFF9593,0xFFFFB8E4,0xFFFF9236,0xFFFFBE32,0xFFFF8F1E,0xFFFFC3AA,0xFFFF8C4B,0xFFFFC946,0xFFFF89BF,0xFFFFCF05,0xFFFF877C,0xFFFFD4E1,0xFFFF8583,0xFFFFDAD8,0xFFFF83D7,0xFFFFE0E7,0xFFFF8276,0xFFFFE708,0xFFFF8163,0xFFFFED38,0xFFFF809E,0xFFFFF375,0xFFFF8028,0xFFFFF9B9



fft8xuanzhuanyinzi:

        .int 0x8000,0x0000,0x7FF6,0xFFFFFCDC,0x7FD8,0xFFFFF9B9,0x7FA7,0xFFFFF696,0x7F62,0xFFFFF375,0x7F09,0xFFFFF055,0x7E9D,0xFFFFED38,0x7E1D,0xFFFFEA1E,0x7D8A,0xFFFFE708,0x7CE3,0xFFFFE3F5,0x7C29,0xFFFFE0E7,0x7B5D,0xFFFFDDDD,0x7A7D,0xFFFFDAD8,0x798A,0xFFFFD7DA,0x7884,0xFFFFD4E1,0x776C,0xFFFFD1EF,0x7641,0xFFFFCF05,0x7504,0xFFFFCC22,0x73B5,0xFFFFC946,0x7255,0xFFFFC674,0x70E2,0xFFFFC3AA,0x6F5F,0xFFFFC0E9,0x6DCA,0xFFFFBE32,0x6C24,0xFFFFBB86,0x6A6D,0xFFFFB8E4,0x68A6,0xFFFFB64C,0x66CF,0xFFFFB3C1,0x64E8,0xFFFFB141,0x62F2,0xFFFFAECD,0x60EC,0xFFFFAC65,0x5ED7,0xFFFFAA0B,0x5CB4,0xFFFFA7BE,0x5A82,0xFFFFA57E,0x5842,0xFFFFA34C,0x55F5,0xFFFFA129,0x539B,0xFFFF9F14,0x5133,0xFFFF9D0E,0x4EBF,0xFFFF9B18,0x4C3F,0xFFFF9931,0x49B4,0xFFFF975A,0x471C,0xFFFF9593,0x447A,0xFFFF93DC,0x41CE,0xFFFF9236,0x3F17,0xFFFF90A1,0x3C56,0xFFFF8F1E,0x398C,0xFFFF8DAB,0x36BA,0xFFFF8C4B,0x33DE,0xFFFF8AFC,0x30FB,0xFFFF89BF,0x2E11,0xFFFF8894,0x2B1F,0xFFFF877C,0x2826,0xFFFF8676,0x2528,0xFFFF8583,0x2223,0xFFFF84A3,0x1F19,0xFFFF83D7,0x1C0B,0xFFFF831D,0x18F8,0xFFFF8276,0x15E2,0xFFFF81E3,0x12C8,0xFFFF8163,0x0FAB,0xFFFF80F7,0x0C8B,0xFFFF809E,0x096A,0xFFFF8059,0x0647,0xFFFF8028,0x0324,0xFFFF800A,0x0000,0xFFFF8000,0xFFFFFCDC,0xFFFF800A,0xFFFFF9B9,0xFFFF8028,0xFFFFF696,0xFFFF8059,0xFFFFF375,0xFFFF809E,0xFFFFF055,0xFFFF80F7,0xFFFFED38,0xFFFF8163,0xFFFFEA1E,0xFFFF81E3,0xFFFFE708,0xFFFF8276,0xFFFFE3F5,0xFFFF831D,0xFFFFE0E7,0xFFFF83D7,0xFFFFDDDD,0xFFFF84A3,0xFFFFDAD8,0xFFFF8583,0xFFFFD7DA,0xFFFF8676,0xFFFFD4E1,0xFFFF877C,0xFFFFD1EF,0xFFFF8894,0xFFFFCF05,0xFFFF89BF,0xFFFFCC22,0xFFFF8AFC,0xFFFFC946,0xFFFF8C4B,0xFFFFC674,0xFFFF8DAB,0xFFFFC3AA,0xFFFF8F1E,0xFFFFC0E9,0xFFFF90A1,0xFFFFBE32,0xFFFF9236,0xFFFFBB86,0xFFFF93DC,0xFFFFB8E4,0xFFFF9593,0xFFFFB64C,0xFFFF975A,0xFFFFB3C1,0xFFFF9931,0xFFFFB141,0xFFFF9B18,0xFFFFAECD,0xFFFF9D0E,0xFFFFAC65,0xFFFF9F14,0xFFFFAA0B,0xFFFFA129,0xFFFFA7BE,0xFFFFA34C,0xFFFFA57E,0xFFFFA57E,0xFFFFA34C,0xFFFFA7BE,0xFFFFA129,0xFFFFAA0B,0xFFFF9F14,0xFFFFAC65,0xFFFF9D0E,0xFFFFAECD,0xFFFF9B18,0xFFFFB141,0xFFFF9931,0xFFFFB3C1,0xFFFF975A,0xFFFFB64C,0xFFFF9593,0xFFFFB8E4,0xFFFF93DC,0xFFFFBB86,0xFFFF9236,0xFFFFBE32,0xFFFF90A1,0xFFFFC0E9,0xFFFF8F1E,0xFFFFC3AA,0xFFFF8DAB,0xFFFFC674,0xFFFF8C4B,0xFFFFC946,0xFFFF8AFC,0xFFFFCC22,0xFFFF89BF,0xFFFFCF05,0xFFFF8894,0xFFFFD1EF,0xFFFF877C,0xFFFFD4E1,0xFFFF8676,0xFFFFD7DA,0xFFFF8583,0xFFFFDAD8,0xFFFF84A3,0xFFFFDDDD,0xFFFF83D7,0xFFFFE0E7,0xFFFF831D,0xFFFFE3F5,0xFFFF8276,0xFFFFE708,0xFFFF81E3,0xFFFFEA1E,0xFFFF8163,0xFFFFED38,0xFFFF80F7,0xFFFFF055,0xFFFF809E,0xFFFFF375,0xFFFF8059,0xFFFFF696,0xFFFF8028,0xFFFFF9B9,0xFFFF800A,0xFFFFFCDC

        

.section .text

vectors:        

        .word STACKINIT         

        .word _start + 1        

        .word _nmi_handler + 1  

        .word _hard_fault  + 1  

        .word 0 

        .word 0    

        .word 0

        .word 0

        .word 0

        .word 0

        .word 0

        .word _svc_handler +1

        .word 0 

        .word 0

        .word _pendsv_handler +1

        .align 2

_start:

_shizhong:                             @时钟设置

        ldr r2, = 0x40022000   @FLASH访问控制

        movs r1, # 0x32

        str r1, [r2]

        ldr r0, = 0x40021000 @ rcc

        @0x34时钟控制寄存器 2 (RCC_CR2)

        movs r1, # 0x01

        str r1, [r0, # 0x34]  @ HSI开14M时钟

_dengdai14mshizhongwending:            @等14M时钟稳定

        ldr r1, [r0, # 0x34]

        lsls r1, r1, # 30     @ 左移30位

        bpl _dengdai14mshizhongwending  @ 等待14M时钟稳定



_neicunqingling:                                 @ 0x1000的内存清零

                                         @ 1K=1024BIT=0X400

        ldr r0, = 0x20000000

        movs r1, # 0

        ldr r3, = 0x1000

_neicunqinglingxunhuan:                           @ 内存清零循环

        subs r3, # 4

        str r1, [r0, r3]

        bne _neicunqinglingxunhuan                @







        

_fftjisuan:

_fft1:        

        ldr r0, = shuru

        ldr r1, = 0x20000000

        movs r2, # 128

        ldr r3, = hudieweifanzhuan

_fft1xunhuan:

        ldr r6, [r3]

        ldr r7, [r3, # 0x04]

        ldr r6, [r0, r6]

        ldr r7, [r0, r7]

        adds r4, r6, r7

        subs r5, r6, r7

        asrs r4, r4, # 1

        asrs r5, r5, # 1

        str r4, [r1]

        str r5, [r1, # 0x04]

        adds r1, r1, # 0x08

        adds r3, r3, # 0x08

        subs r2, r2, # 1

        bne _fft1xunhuan

        

_fft2:

        ldr r0, = 0x20000000

        movs r4, # 1

        lsls r4, r4, # 10

        adds r4, r4, r0

        mov r8, r4

_fft2xunhuan:

        ldr r4, [r0]

        ldr r5, [r0, # 0x08]

        ldr r6, [r0, # 0x04]

        ldr r7, [r0, # 0x0c]

        adds r1, r4, r5

        subs r2, r4, r5

        mov r3, r6                @0r

        movs r4, # 0        

        subs r4, r4, r7                @0i

        mov r5, r6                @3r

        mov r6, r7                @3i

        movs r7, # 1

        lsls r7, r7, # 10

        adds r7, r7, r0

        str r1, [r0]

        str r2, [r0, # 0x08]

        str r3, [r0, # 0x04]

        str r4, [r7, # 0x04]

        str r5, [r0, # 0x0c]

        str r6, [r7, # 0x0c]

        adds r0, r0, # 0x10

        cmp r0, r8

        bne _fft2xunhuan

_fft3:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft3xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 0x10

        mov r11, r5

        movs r5, # 4

        mov r12, r5

        bl _fftg

_fft4:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft4xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 0x20

        mov r11, r5

        movs r5, # 8

        mov r12, r5

        bl _fftg

_fft5:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft5xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 0x40

        mov r11, r5

        movs r5, # 16

        mov r12, r5

        bl _fftg



_fft6:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft6xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 0x80

        mov r11, r5

        movs r5, # 32

        mov r12, r5

        bl _fftg

        

_fft7:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft7xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 1

        lsls r5, r5, # 8

        mov r11, r5

        movs r5, # 64

        mov r12, r5

        bl _fftg



_fft8:

        ldr r6, = xuanzhuanyinzi

        ldr r2, = fft8xuanzhuanyinzi

        ldr r0, = 0x20000000

        str r2, [r6]

        movs r1, # 1

        lsls r1, r1, # 10

        adds r1, r1, r0

        mov r8, r1

        mov r9, r0

        mov r10, r2

        movs r5, # 1

        lsls r5, r5, # 9

        mov r11, r5

        movs r5, # 128

        mov r12, r5

        bl _fftg

        

tingting:

        b tingting

_fftjisuanfuzhi:

        ldr r0, = 0x20000000

        ldr r1, = 0x20000400

        mov r8, r1

_jisuanfuzhixunhuan:

        ldr r2, [r0]

        ldr r3, [r1]

        movs r3, r3

        bpl _fzbushifushu1

        mvns r3, r3

        adds r3, r3, # 1

_fzbushifushu1:        

        asrs r2, r2, # 1

        bpl _fzbushifushu

        mvns r2, r2

        adds r2, r2, # 1

_fzbushifushu:

        adds r3, r3, r2

        lsls r3, r3, # 1

        str r3, [r0, r4]

        adds r0, r0, # 4

        adds r1, r1, # 4

        cmp r0, r8

        bne _jisuanfuzhixunhuan

        bx lr

_fftg:

        push {lr}

        movs r4, # 0

        mov lr, r4

_fftxunhuan:

        mov r0, r9

        mov r1, r8

        mov r2, r10

        mov r3, r11

        ldr r4, [r0]

        ldr r5, [r1]

        ldr r6, [r0, r3]

        ldr r7, [r1, r3]

        ldr r3, [r2]                @sr

        ldr r2, [r2, # 0x04]        @si

        push {r4,r5}

        mov r4, r6

        muls r4, r4, r3

        mov r5, r7

        muls r5, r5, r2

        subs r4, r4, r5                @r

        asrs r4, r4, # 15

        mov r5, r6

        muls r5, r5, r2

        muls r7, r7, r3

        adds r7, r7, r5    @i

        asrs r7, r7, # 15

        pop {r2,r5}

        adds r3, r2, r4    @0r

        subs r2, r2, r4    @1r

        adds r4, r5, r7

        subs r5, r5, r7

        mov r6, r11

        str r3, [r0]

        str r4, [r1]

        str r2, [r0, r6]

        str r5, [r1, r6]

        adds r0, r0, # 0x04

        adds r1, r1, # 0x04

        mov r9, r0

        mov r8, r1

        mov r2, r10

        adds r2, r2, # 0x08

        mov r10, r2

        mov r4, lr

        adds r4, r4, # 1

        mov lr, r4

        mov r7, r12

        cmp r4, r7

        bne _fftxunhuan

        movs  r4, # 0

        ldr r6, = xuanzhuanyinzi

        ldr r5, = 0x20000400

        ldr r6, [r6]

        mov r10, r6

        mov lr, r4

        mov r7, r11

        adds r0, r0, r7

        adds r1, r1, r7

        mov r9, r0

        mov r8, r1

        cmp r0, r5

        bne _fftxunhuan

        pop {pc}

        .ltorg

_nmi_handler:

        bx lr

_hard_fault:

        bx lr

_svc_handler:

        bx lr

_pendsv_handler:

        bx lr