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High Pass Filter coefficients file



//高通滤波系数文件



Company:



Microchip Technology Inc.



File Name:



examplehpf.s



Summary:



Consists of coefficients used by the filter function



//包含了滤波函数的系数



Description:



This file composes of the high pass filter coefficients that are used



by the IIRTransposed filter function to filter the incoming analog



signal. These coefficients reside in the x-memory area.



//这些系数存在于X-memory存储区域



*******************************************************************************/



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Copyright (c) 2012 released Microchip Technology Inc.  All rights reserved.



Microchip licenses to you the right to use, modify, copy and distribute



Software only when embedded on a Microchip microcontroller or digital signal



controller that is integrated into your product or third party product



(pursuant to the sublicense terms in the accompanying license agreement).



You should refer to the license agreement accompanying this Software for



additional information regarding your rights and obligations.



SOFTWARE AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,



EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF



MERCHANTABILITY, TITLE, NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE.



IN NO EVENT SHALL MICROCHIP OR ITS LICENSORS BE LIABLE OR OBLIGATED UNDER



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SUBSTITUTE GOODS, TECHNOLOGY, SERVICES, OR ANY CLAIMS BY THIRD PARTIES



(INCLUDING BUT NOT LIMITED TO ANY DEFENSE THEREOF), OR OTHER SIMILAR COSTS.



*******************************************************************************/



; *****************************************************************************



; *****************************************************************************



; Section: Constants



; *****************************************************************************



; *****************************************************************************



.equ ExampleHPFNumSections, 5



; ..............................................................................



;



; Allocate and initialize filter coefficients



;



; These coefficients have been designed for use in the Transpose filter only



.section .xdata, xmemory, data  ;THIS line was modified



;to be compatible with C30 v1.3x



ExampleHPFCoefs:



.hword  0x2392  ; b( 1,0)/2



.hword  0xB8FF  ; b( 1,1)/2



.hword  0x3D5F  ; a( 1,1)/2



.hword  0x2392  ; b( 1,2)/2



.hword  0xEF39  ; a( 1,2)/2



.hword  0x2FBB  ; b( 2,0)/2



.hword  0xA1F2  ; b( 2,1)/2



.hword  0x579D  ; a( 2,1)/2



.hword  0x2FBB  ; b( 2,2)/2



.hword  0xDA17  ; a( 2,2)/2



.hword  0x3818  ; b( 3,0)/2



.hword  0x9344  ; b( 3,1)/2



.hword  0x68F9  ; a( 3,1)/2



.hword  0x3818  ; b( 3,2)/2



.hword  0xCC0D  ; a( 3,2)/2



.hword  0x3C51  ; b( 4,0)/2



.hword  0x8C80  ; b( 4,1)/2



.hword  0x7150  ; a( 4,1)/2



.hword  0x3C51  ; b( 4,2)/2



.hword  0xC52E  ; a( 4,2)/2



.hword  0x3E73  ; b( 5,0)/2



.hword  0x8920  ; b( 5,1)/2



.hword  0x7583  ; a( 5,1)/2



.hword  0x3E73  ; b( 5,2)/2



.hword  0xC175  ; a( 5,2)/2



; ..............................................................................



; Allocate states buffers in (uninitialized) Y data space



.section .yconst



ExampleHPFStates1:



.space ExampleHPFNumSections*2



ExampleHPFStates2:



.space ExampleHPFNumSections*2



; ..............................................................................



; Allocate and intialize filter structure



;配置和初始化，滤波器结构体



.section .data



.global _ExampleHPFFilter



;这个是对ExampleHPFFilter定义么？？？？否则该变量是在哪里定义的？？



_ExampleHPFFilter:



.hword ExampleHPFNumSections-1



.hword ExampleHPFCoefs



.hword 0xFF00



.hword ExampleHPFStates1



.hword ExampleHPFStates2



.hword 0x0000



; ..............................................................................



; Sample assembly language calling program



;  The following declarations can be cut and pasted as needed into a program



;               .extern _IIRTransposeFilterInit



;               .extern _BlockIIRTransposeFilter



;               .extern _ExampleHPFFilter



;



;               .section        .bss



;



;        The input and output buffers can be made any desired size



;          the value 40 is just an example - however, one must ensure



;          that the output buffer is at least as long as the number of samples



;          to be filtered (parameter 4)



;input:         .space  40



;output:        .space  40



;               .text



;



;



;  This code can be copied and pasted as needed into a program



;



;



; Set up pointers to access input samples, filter taps, delay line and



; output samples.



;               mov     #_ExampleHPFFilter, W0  ; Initalize W0 to filter structure



;               call    _IIRTransposeFilterInit ; call this function once



;



; The next 4 instructions are required prior to each subroutine call



; to _BlockIIRTransposeFilter



;               mov     #_ExampleHPFFilter, W0  ; Initalize W0 to filter structure



;               mov     #input, W1      ; Initalize W1 to input buffer



;               mov     #output, W2     ; Initalize W2 to output buffer



;               mov     #20, W3 ; Initialize W3 with number of required output samples



;               call    _BlockIIRTransposeFilter        ; call as many times as needed