PDM to PCM 代码
18028703418.syntax unified
.cpu cortex-m4
.fpu fpv4-sp-d16
@; .eabi_attribute 20, 1
@; .eabi_attribute 21, 1
@; .eabi_attribute 23, 3
@; .eabi_attribute 24, 1
@; .eabi_attribute 25, 1
@; .eabi_attribute 26, 2
@; .eabi_attribute 30, 2
@; .eabi_attribute 18, 2
.thumb
@; ===========================================================================
@; Segment type: Externs
@; ===========================================================================
.global __aeabi_fcmpeq
.global __aeabi_fmul
.global __aeabi_f2d
.global __aeabi_i2d
.global __aeabi_ddiv
.global __aeabi_dadd
.global __aeabi_d2uiz
.global __aeabi_dmul
@; ===========================================================================
.section .text.PDM_Filter_Init
.code 16
.weak PDM_Filter_Init
.type PDM_Filter_Init, %function
@; ===========================================================================
PDM_Filter_Init:
PUSH.W {R3-R11,LR}
@; LDR R2, =0xF407A5C2 @test data
@; LDR R3, =0x40023000 @CRC BASE
MOV R5, R0
@; STR R2, @load 0xF407A5C2 into crc data register
@; LDR R3, @get contents of crc data register
@; LDR R2, =0xB5E8B5CD @load control word
MOVS R6, #0
@; CMP R3, R2 @compare crc32 and awaited result
@; BNE loc_42 @ Checking that it's really CPU, that manufatured by ST.
@; LDR R2, =stm32_crc @get contents of
LDR R7, @LP_HZ
ADD.W R4, R0, #0x10
@; STR R3, @save 0xB5E8B5CD into =stm32_crc variable
STR R6,
STR R6,
STR R6,
STR R6,
STR R6,
STR R6,
STR R6,
MOV R0, R7
MOVS R1, #0
BL __aeabi_fcmpeq @fcmpeq(LP_HZ, 0)
CBZ R0, loc_44
B loc_90
@; ---------------------------------------------------------------------------
@;
@;loc_42:
@; B loc_42
@; ---------------------------------------------------------------------------
loc_44:
MOV R0, R7
MOV.W R1, #0x43800000
BL __aeabi_fmul
BL __aeabi_f2d
MOV R8, R0
MOV R0, R7
MOV R9, R1
BL __aeabi_f2d
MOV R6, R0
LDRH R0,
MOV R7, R1
BL __aeabi_i2d
ADR R3, dword_F8
LDRD.W R2, R3,
BL __aeabi_ddiv
MOV R2, R0
MOV R3, R1
MOV R0, R6
MOV R1, R7
BL __aeabi_dadd
MOV R2, R0
MOV R3, R1
MOV R0, R8
MOV R1, R9
BL __aeabi_ddiv
BL __aeabi_d2uiz
STRH R0,
B loc_92
@; ---------------------------------------------------------------------------
loc_90:
STRH R6,
loc_92:
LDR R7,
MOVS R1, #0
MOV R0, R7
BL __aeabi_fcmpeq
CBNZ R0, loc_E4
LDRH R6,
LSLS R0, R6, #8
BL __aeabi_i2d
MOV R10, R0
MOV R0, R7
MOV R11, R1
BL __aeabi_f2d
ADR R3, dword_F8
LDRD.W R2, R3,
BL __aeabi_dmul
MOV R8, R0
MOV R0, R6
MOV R9, R1
BL __aeabi_i2d
MOV R2, R0
MOV R3, R1
MOV R0, R8
MOV R1, R9
BL __aeabi_dadd
MOV R2, R0
MOV R3, R1
MOV R0, R10
MOV R1, R11
BL __aeabi_ddiv
BL __aeabi_d2uiz
STRH R0,
B loc_E8
@; ---------------------------------------------------------------------------
loc_E4:
MOVS R3, #0
STRH R3,
loc_E8:
LDRH R2,
MOV.W R3, #0x3E8
UDIV.W R3, R2, R3
STRH R3,
POP.W {R3-R11,PC}
@; End of function PDM_Filter_Init
@; ---------------------------------------------------------------------------
.align 8
dword_F8:
.word 0x51EB851F, 0x40191EB8
@;dword_100:
@; .word 0xF407A5C2
@;dword_104:
@; .word 0x40023000
@;dword_108:
@; .word 0xB5E8B5CD
@;off_10C:
@; .word stm32_crc @; DATA XREF: PDM_Filter_Init+16r
@ENDP
.size PDM_Filter_Init, .-PDM_Filter_Init
@; ===========================================================================
.section .text.PDM_Filter_64_LSB
.code 16
.weak PDM_Filter_64_LSB
.type PDM_Filter_64_LSB, %function
@; ===========================================================================
PDM_Filter_64_LSB:
var_A4 = -0xA4
var_9C = -0x9C
var_94 = -0x94
var_90 = -0x90
var_8C = -0x8C
var_88 = -0x88
var_84 = -0x84
var_80 = -0x80
var_7C = -0x7C
var_78 = -0x78
var_74 = -0x74
var_70 = -0x70
var_6C = -0x6C
var_68 = -0x68
var_64 = -0x64
var_60 = -0x60
var_5C = -0x5C
var_58 = -0x58
var_54 = -0x54
var_50 = -0x50
var_4C = -0x4C
var_48 = -0x48
var_44 = -0x44
var_40 = -0x40
var_3C = -0x3C
var_38 = -0x38
var_34 = -0x34
var_30 = -0x30
var_2C = -0x2C
PUSH.W {R4-R11,LR}
SUB SP, SP, #0x84
STR R2,
@; LDR R2, =stm32_crc @load address of stm32_crc
STR R1,
@; LDR R1, @load 0xB5E8B5CD that in stm32_crc ram var
@; LDR R2, =0xB5E8B5CD @load awaited value
@; CMP R1, R2
@; BEQ loc_126 @if all ok, do the stuff
@;
@;loc_124:
@; B loc_124
@; ---------------------------------------------------------------------------
loc_126:
ADD.W R2, R3, #0x10
LDR R4,
LDR R1,
STR R4,
LDR R4,
STR R1,
LDR R1,
STR R4,
LDRH R4,
STR R1,
LDRH R1,
LDR R5,
STR R4,
MOVS R4, #6
MULS R4, R1
STR R5,
LDRH R5,
MOV.W R9, R1,LSL#2
MOV.W R11, R1,LSL#3
STR R5,
LSLS R5, R1, #1
ADD.W R8, R5, R1
ADD.W R10, R9, R1
STR R4,
RSB.W R12, R1, R11
MOVS R4, #0
LDR R7,
LDR R6,
STR R5,
STR.W R8,
STR.W R9,
STR.W R10,
STR.W R11,
STR.W R12,
STR R4,
STR R1,
STR R3,
B loc_3B0
@; ---------------------------------------------------------------------------
loc_188:
LDRB.W R8,
LDR.W R10, =T2
LDR R5,
LDRB.W R4,
LDR.W R9,
ADDS R6, R6, R4
STR R6,
LDRB.W R12,
LDR R6, =T1
LDRB.W R4,
LDRB.W R5,
LDR R1,
ADD.W R4, R4, R5,LSL#1
ADDS R7, R4, R7
STR R7,
LDRB.W R4,
LDR R7, =T0
LDRB.W R5,
LDRB.W R8,
LDRB.W R11,
ADD R5, R8
LDRB.W R8,
LDRB.W R9,
ADD.W R5, R5, R8,LSL#1
LDRB.W R8,
LDRB.W R12,
ADD R9, R8
ADD.W R12, R9, R12,LSL#1
LDR R3,
STR.W R12,
LDRB.W R9,
LDRB R4,
LDRB.W R12,
LDRB.W R8,
ADD R4, R12
ADD.W R8, R4, R8,LSL#1
LDR R4,
STR.W R8,
ADD R4, R8
LDR.W R8,
STR R4,
LDRB.W R12,
LDRB.W R8,
LDRB.W R4,
LDR R1,
ADD R4, R8
LDRB.W R8,
LDRB.W R9,
ADD.W R4, R4, R8,LSL#1
ADD.W R11, R4, R5
STR.W R11,
LDRB.W R8,
LDRB.W R11,
ADD R9, R11
LDRB.W R11,
ADD.W R11, R9, R11,LSL#1
STR.W R11,
LDR R3,
LDRB.W R12,
ADD R3, R11
LDR.W R11,
STR R3,
LDRB.W R9,
LDRB.W R11,
LDRB.W R10,
LDR R1,
ADD R12, R10
ADD.W R11, R12, R11,LSL#1
LDR.W R12,
MOV.W R10, R5,LSL#4
ADD R12, R11
STR.W R12,
RSB.W R10, R5, R10
LDRB.W R12,
MOV.W R8, #0xA
MLA.W R10, R8, R1, R10
LDRB.W R6,
LDR R3,
STR.W R11,
ADD R10, R3
LDR.W R11,
ADD.W R6, R12, R6,LSL#1
ADD.W R12, R4, R4,LSL#1
ADD R10, R12
LDRB.W R7,
MOV.W R9, #6
MLA.W R10, R9, R11, R10
LDR R1,
LDR R3,
ADD R10, R1
MOV.W R12, #0x1C
MLA.W R10, R12, R3, R10
LDR R1,
MOV.W R11, #0x15
MLA.W R10, R11, R1, R10
LDR R3,
STR.W R10,
MOV.W R10, #0x2E @; '.'
MUL.W R10, R10, R3
LDR R1,
MOVS R3, #0x30 @; '0'
MLA.W R10, R3, R1, R10
LDR R1,
LDR R3,
ADD R1, R10
MOV.W R10, #0x24 @; '$'
MLA.W R3, R10, R3, R1
LDR R1,
ADD R10, R9
MLA.W R1, R10, R1, R3
STR R1,
LDR R1,
ADD.W R5, R5, R5,LSL#1
MLA.W R9, R9, R1, R5
LSLS R5, R4, #4
SUBS R4, R5, R4
LDR R3,
ADD R9, R4
MLA.W R9, R8, R3, R9
LDR R4,
LDR R5,
MLA.W R9, R12, R4, R9
MLA.W R9, R11, R5, R9
LDR R1,
LDR R3,
LDR R4,
ADD R1, R9
STR R1,
SUB.W R10, R3, #0x20000
CBZ R4, loc_33E
LDR R5,
LDR R1,
LDR R3,
SUBS R4, R5, R1
ADD R4, R10
MULS R4, R3
IT MI
ADDMI R4, #0xFF
ASRS R4, R4, #8
STR.W R10,
STR R4,
MOV R10, R4
loc_33E:
LDR R4,
CBZ R4, loc_35C
LDR R5,
RSB.W R4, R4, #0x100
MULS R4, R5
LDR R1,
MLA.W R4, R1, R10, R4
CMP R4, #0
IT LT
ADDLT R4, #0xFF
ASRS R4, R4, #8
STR R4,
MOV R10, R4
loc_35C:
LDR R3,
MUL.W R10, R3, R10
CMP.W R10, #0
BLE loc_372
ADD.W R10, R10, #8
MOV.W R10, R10,ASR#4
B loc_380
@; ---------------------------------------------------------------------------
loc_372:
SUBS.W R12, R10, #8
IT MI
ADDMI.W R12, R10, #7
MOV.W R10, R12,ASR#4
loc_380:
LDR R5,
LDR.W R8,
LDRH R4,
MOVW R12, #0x7FBC
MUL.W R4, R4, R8
LDR R5, =0xFFFF8044
CMP R10, R12
IT LT
MOVLT R12, R10
LDR R1,
LDR R3,
CMP R12, R5
IT GE
MOVGE R5, R12
ADD.W R8, R8, #1
STRH.W R5,
ADDS R0, R0, R3
STR.W R8,
loc_3B0:
LDRH R4,
LDR R5,
CMP R5, R4
BLT.W loc_188
LDR R3,
LDR R1,
STR R7,
LDR R3,
STR R1,
STR R3,
LDR R5,
LDR R1,
LDR R3,
STR R6,
STR R5,
STR R1,
STR R3,
MOV R0, R4
ADD SP, SP, #0x84
POP.W {R4-R11,PC}
@; End of function PDM_Filter_64_LSB
@; ---------------------------------------------------------------------------
@;off_3DC:
@; .word stm32_crc
@;dword_3E0:
@; .word 0xB5E8B5CD
off_3E4:
.word T1
off_3E8:
.word T0
dword_3EC:
.word 0xFFFF8044
off_3F0:
.word T2
@; .text.PDM_Filter_64_LSB ends
@ENDP
.size PDM_Filter_64_LSB, .-PDM_Filter_64_LSB
@; Segment type: Uninitialized
@; .section .bss.stm32_crc
@; @; ORG 0xCEC
@; .global stm32_crc
@; stm32_crc % 4
@; .bss.stm32_crc ends
@; ===========================================================================
@; ===========================================================================
@; Segment type: Pure data
.section .data.T0
.align 0
@; ORG 0xCF0
@.export T0
@; ===========================================================================
T0:
.byte 0,0x1C,0x15,0x31, 0xF, 0x2B, 0x24,0x40
.byte 0xA,0x26,0x1F,0x3B,0x19, 0x35, 0x2E,0x4A
.byte 6,0x22,0x1B,0x37,0x15, 0x31, 0x2A,0x46
.byte 0x10,0x2C,0x25,0x41,0x1F, 0x3B, 0x34,0x50
.byte 3,0x1F,0x18,0x34,0x12, 0x2E, 0x27,0x43
.byte 0xD,0x29,0x22,0x3E,0x1C, 0x38, 0x31,0x4D
.byte 9,0x25,0x1E,0x3A,0x18, 0x34, 0x2D,0x49
.byte 0x13,0x2F,0x28,0x44,0x22, 0x3E, 0x37,0x53
.byte 1,0x1D,0x16,0x32,0x10, 0x2C, 0x25,0x41
.byte 0xB,0x27,0x20,0x3C,0x1A, 0x36, 0x2F,0x4B
.byte 7,0x23,0x1C,0x38,0x16, 0x32, 0x2B,0x47
.byte 0x11,0x2D,0x26,0x42,0x20, 0x3C, 0x35,0x51
.byte 4,0x20,0x19,0x35,0x13, 0x2F, 0x28,0x44
.byte 0xE,0x2A,0x23,0x3F,0x1D, 0x39, 0x32,0x4E
.byte 0xA,0x26,0x1F,0x3B,0x19, 0x35, 0x2E,0x4A
.byte 0x14,0x30,0x29,0x45,0x23, 0x3F, 0x38,0x54
.byte 0,0x1C,0x15,0x31, 0xF, 0x2B, 0x24,0x40
.byte 0xA,0x26,0x1F,0x3B,0x19, 0x35, 0x2E,0x4A
.byte 6,0x22,0x1B,0x37,0x15, 0x31, 0x2A,0x46
.byte 0x10,0x2C,0x25,0x41,0x1F, 0x3B, 0x34,0x50
.byte 3,0x1F,0x18,0x34,0x12, 0x2E, 0x27,0x43
.byte 0xD,0x29,0x22,0x3E,0x1C, 0x38, 0x31,0x4D
.byte 9,0x25,0x1E,0x3A,0x18, 0x34, 0x2D,0x49
.byte 0x13,0x2F,0x28,0x44,0x22, 0x3E, 0x37,0x53
.byte 1,0x1D,0x16,0x32,0x10, 0x2C, 0x25,0x41
.byte 0xB,0x27,0x20,0x3C,0x1A, 0x36, 0x2F,0x4B
.byte 7,0x23,0x1C,0x38,0x16, 0x32, 0x2B,0x47
.byte 0x11,0x2D,0x26,0x42,0x20, 0x3C, 0x35,0x51
.byte 4,0x20,0x19,0x35,0x13, 0x2F, 0x28,0x44
.byte 0xE,0x2A,0x23,0x3F,0x1D, 0x39, 0x32,0x4E
.byte 0xA,0x26,0x1F,0x3B,0x19, 0x35, 0x2E,0x4A
.byte 0x14,0x30,0x29,0x45,0x23, 0x3F, 0x38,0x54
@; .data.T0 ends
.size T0, .-T0
@; ===========================================================================
@; Segment type: Pure data
.section .data.T1
.align 0
@; ORG 0xDF0
@.export T1
@; ===========================================================================
T1:
.byte 0,0x12,0x15,0x27,0x17, 0x29, 0x2C,0x3E
.byte 0x18,0x2A,0x2D,0x3F,0x2F, 0x41, 0x44,0x56
.byte 0x18,0x2A,0x2D,0x3F,0x2F, 0x41, 0x44,0x56
.byte 0x30,0x42,0x45,0x57,0x47, 0x59, 0x5C,0x6E
.byte 0x17,0x29,0x2C,0x3E,0x2E, 0x40, 0x43,0x55
.byte 0x2F,0x41,0x44,0x56,0x46, 0x58, 0x5B,0x6D
.byte 0x2F,0x41,0x44,0x56,0x46, 0x58, 0x5B,0x6D
.byte 0x47,0x59,0x5C,0x6E,0x5E, 0x70, 0x73,0x85
.byte 0x15,0x27,0x2A,0x3C,0x2C, 0x3E, 0x41,0x53
.byte 0x2D,0x3F,0x42,0x54,0x44, 0x56, 0x59,0x6B
.byte 0x2D,0x3F,0x42,0x54,0x44, 0x56, 0x59,0x6B
.byte 0x45,0x57,0x5A,0x6C,0x5C, 0x6E, 0x71,0x83
.byte 0x2C,0x3E,0x41,0x53,0x43, 0x55, 0x58,0x6A
.byte 0x44,0x56,0x59,0x6B,0x5B, 0x6D, 0x70,0x82
.byte 0x44,0x56,0x59,0x6B,0x5B, 0x6D, 0x70,0x82
.byte 0x5C,0x6E,0x71,0x83,0x73, 0x85, 0x88,0x9A
.byte 0x12,0x24,0x27,0x39,0x29, 0x3B, 0x3E,0x50
.byte 0x2A,0x3C,0x3F,0x51,0x41, 0x53, 0x56,0x68
.byte 0x2A,0x3C,0x3F,0x51,0x41, 0x53, 0x56,0x68
.byte 0x42,0x54,0x57,0x69,0x59, 0x6B, 0x6E,0x80
.byte 0x29,0x3B,0x3E,0x50,0x40, 0x52, 0x55,0x67
.byte 0x41,0x53,0x56,0x68,0x58, 0x6A, 0x6D,0x7F
.byte 0x41,0x53,0x56,0x68,0x58, 0x6A, 0x6D,0x7F
.byte 0x59,0x6B,0x6E,0x80,0x70, 0x82, 0x85,0x97
.byte 0x27,0x39,0x3C,0x4E,0x3E, 0x50, 0x53,0x65
.byte 0x3F,0x51,0x54,0x66,0x56, 0x68, 0x6B,0x7D
.byte 0x3F,0x51,0x54,0x66,0x56, 0x68, 0x6B,0x7D
.byte 0x57,0x69,0x6C,0x7E,0x6E, 0x80, 0x83,0x95
.byte 0x3E,0x50,0x53,0x65,0x55, 0x67, 0x6A,0x7C
.byte 0x56,0x68,0x6B,0x7D,0x6D, 0x7F, 0x82,0x94
.byte 0x56,0x68,0x6B,0x7D,0x6D, 0x7F, 0x82,0x94
.byte 0x6E,0x80,0x83,0x95,0x85, 0x97, 0x9A,0xAC
@; .data.T1 ends
.size T1, .-T1
@; ===========================================================================
@; Segment type: Pure data
.section .data.T2
.align 0
@; ORG 0xEF0
@.export T2
@; ===========================================================================
T2:
.byte 0, 0, 1, 1, 3, 3, 4, 4
.byte 6, 6, 7, 7, 9, 9, 0xA, 0xA
.byte 0xA, 0xA, 0xB, 0xB, 0xD, 0xD, 0xE, 0xE
.byte 0x10,0x10,0x11,0x11,0x13, 0x13, 0x14,0x14
.byte 0xF, 0xF,0x10,0x10,0x12, 0x12, 0x13,0x13
.byte 0x15,0x15,0x16,0x16,0x18, 0x18, 0x19,0x19
.byte 0x19,0x19,0x1A,0x1A,0x1C, 0x1C, 0x1D,0x1D
.byte 0x1F,0x1F,0x20,0x20,0x22, 0x22, 0x23,0x23
.byte 0x15,0x15,0x16,0x16,0x18, 0x18, 0x19,0x19
.byte 0x1B,0x1B,0x1C,0x1C,0x1E, 0x1E, 0x1F,0x1F
.byte 0x1F,0x1F,0x20,0x20,0x22, 0x22, 0x23,0x23
.byte 0x25,0x25,0x26,0x26,0x28, 0x28, 0x29,0x29
.byte 0x24,0x24,0x25,0x25,0x27, 0x27, 0x28,0x28
.byte 0x2A,0x2A,0x2B,0x2B,0x2D, 0x2D, 0x2E,0x2E
.byte 0x2E,0x2E,0x2F,0x2F,0x31, 0x31, 0x32,0x32
.byte 0x34,0x34,0x35,0x35,0x37, 0x37, 0x38,0x38
.byte 0x1C,0x1C,0x1D,0x1D,0x1F, 0x1F, 0x20,0x20
.byte 0x22,0x22,0x23,0x23,0x25, 0x25, 0x26,0x26
.byte 0x26,0x26,0x27,0x27,0x29, 0x29, 0x2A,0x2A
.byte 0x2C,0x2C,0x2D,0x2D,0x2F, 0x2F, 0x30,0x30
.byte 0x2B,0x2B,0x2C,0x2C,0x2E, 0x2E, 0x2F,0x2F
.byte 0x31,0x31,0x32,0x32,0x34, 0x34, 0x35,0x35
.byte 0x35,0x35,0x36,0x36,0x38, 0x38, 0x39,0x39
.byte 0x3B,0x3B,0x3C,0x3C,0x3E, 0x3E, 0x3F,0x3F
.byte 0x31,0x31,0x32,0x32,0x34, 0x34, 0x35,0x35
.byte 0x37,0x37,0x38,0x38,0x3A, 0x3A, 0x3B,0x3B
.byte 0x3B,0x3B,0x3C,0x3C,0x3E, 0x3E, 0x3F,0x3F
.byte 0x41,0x41,0x42,0x42,0x44, 0x44, 0x45,0x45
.byte 0x40,0x40,0x41,0x41,0x43, 0x43, 0x44,0x44
.byte 0x46,0x46,0x47,0x47,0x49, 0x49, 0x4A,0x4A
.byte 0x4A,0x4A,0x4B,0x4B,0x4D, 0x4D, 0x4E,0x4E
.byte 0x50,0x50,0x51,0x51,0x53, 0x53, 0x54,0x54
@; .data.T2 ends
.size T2, .-T2
@ENDP
.end 不懂汇编，是不是，先低通，然后再抽取？ 楼主就把ST提供的那个“libPDMFilter”给反汇编了一下，然后加个手机号，啥都不说，这样真的好吗？
变量名还是var_A4这样的自动生成的名字。。。楼主要是分析一下，然后把那些变量名改成自己理解的名字那就很有用了。或者楼主分析一下这filter是IIR的还是FIR的，写的好不好，效率怎么样啥的啊。
或者拿网上开源的PDM to PCM代码来给我们分析一下也不错。。。 caixiuwen 发表于 2015-3-8 20:42
楼主就把ST提供的那个“libPDMFilter”给反汇编了一下，然后加个手机号，啥都不说，这样真的好吗？
变量名 ...
网上有开源的PDM转PCM么，目前正好要用到这个功能，但是ST的那个PDM filter库，我没有看懂怎么搞 dudududu 发表于 2015-7-14 10:55
网上有开源的PDM转PCM么，目前正好要用到这个功能，但是ST的那个PDM filter库，我没有看懂怎么搞 ...
以前在网上看到过有人自己写的，分享出来了。不过我没试过。ST的库好像不难用，有个说明文档的。 这个代码的不好用。只能作普通的语音解码。频宽很窄。 并且噪声也大。严重消耗系统资源。
还不如用内置的ADC，做滤波处理。 当然硬件做得要相当过硬。
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