## Forums Search for: Fixed Point

## MIMO Hardware

inHi, Is anyone aware of companies making / selling floating or fixed-point DSP / DSP + FPGA Multiple Antenna PCI / compactPCI boards...

Hi, Is anyone aware of companies making / selling floating or fixed-point DSP / DSP + FPGA Multiple Antenna PCI / compactPCI boards ? Thanx Sarat This message was sent using the Comp.DSP web interface on www.DSPRelated.com

## Antilog - base 10

inHello, I am trying to compute the antilog of a fixed point number 'x' -> 10^(x), to be precise. I do not want to use a look-up table for...

Hello, I am trying to compute the antilog of a fixed point number 'x' -> 10^(x), to be precise. I do not want to use a look-up table for the same. One way this can be done is to use the Taylor series expansion of 10^(x). Can someone point me to the right place? Also any suggestions on improved (in the number of execute cycles, memory is not much of a constraint - only enough to cancel t

## FFT for the StarCore SC140

inAnyone know where I can download a library/function/API for fixed point FFT implementation over the StarCore SC140? T.

Anyone know where I can download a library/function/API for fixed point FFT implementation over the StarCore SC140? T.

## Who Offers Fixed-Point Arithmetic Libraries?

inI know that TI offers a fixed-point arithmetic package for use with the '28xx processors (they call it their "Q15" or "Qxx" package). Does...

I know that TI offers a fixed-point arithmetic package for use with the '28xx processors (they call it their "Q15" or "Qxx" package). Does anyone know of any other vendors that offer this? -- ------------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com

## sqrt on C6414 DSP

inHi ... I was working on the C6414 DSP (fixed point) and needed an sqrt approximation - I finally found a really nice solution (but I have...

Hi ... I was working on the C6414 DSP (fixed point) and needed an sqrt approximation - I finally found a really nice solution (but I have trouble understanding it :-) my assumptions: - fixed point representation - no division ... too slow for me - approximation is fine ... sqrt(a^2 + b^2) ~ max(a,b) + .5min(a,b) was not possible in this case ... my solution: The processor has...

## IIR Filter fixed point DSP

inHi I am trying to design a IIR filter using a 16-bit fixed point DSP. I need to calculate the coeff in the form of second order sections. I...

Hi I am trying to design a IIR filter using a 16-bit fixed point DSP. I need to calculate the coeff in the form of second order sections. I would like to do this with MATLAB. Does anyone have some MATLAB code that will do this. I found a routine on Texas Instrument site but as well as the coeff it creates some scaling factors for the inputs. I dont want this as I have seen other programs such a...

## Fixed-point algorithm for exponential function fitting for an embedded application

inHello, We are seeking a "light" algorithm performing exponential function (y=A*exp(-k*x)) fitting. A typical curve is composed of 200...

Hello, We are seeking a "light" algorithm performing exponential function (y=A*exp(-k*x)) fitting. A typical curve is composed of 200 16-bits integers. As the code should be executed by a MCU, fixed-point is preferable but if floating-point is required for accuracy reasons, it could also be implemented if the amount of calculation is compatible with a reasonable processing time (few hundre...

## Quantization of fixed point filter coefficients.

inThis post is a retake on the 'quantization of filter coefficients' issue. Let me present the issue in the following. I have designed a...

This post is a retake on the 'quantization of filter coefficients' issue. Let me present the issue in the following. I have designed a filter (notch, cut-off 55.7Hz) which is a bi-quad. The transfer function is : H(z) = 1 + (-1.992)*z^-1 + (0.994)*z^-2 -------------------------------- 1 - (-1.836)*z^-1 - (0.852)*z^-2 Now I am implementing this filter on a 16-bit fix...

## scaling in a fixed point FFT

inHi. I'm writting a code to do a FFT using fixed point(16 bits). Well this is the question What is the better, make the sacaling after or...

Hi. I'm writting a code to do a FFT using fixed point(16 bits). Well this is the question What is the better, make the sacaling after or before start a pass. I think that is better before start a pass. This is correct? Diego

## finding e^x in fixed pt format when x is a floating pt

inhi, how can i get an almost accurate value for e^x if x is a floating point number. Say to find e^1.5. In that case 1.5 has to be...

hi, how can i get an almost accurate value for e^x if x is a floating point number. Say to find e^1.5. In that case 1.5 has to be converted to fixed point format, say x'. Then how can I get back e^x from e^x'. Is there an algorithm or a standard implementation that I can refer for the same. Hoping for a help. -- Jagadeesh

## Unsigned Fixed Point Long Division Fractional Divide Function (32 bit/ 32 bit)

inHello all, I am looking for an unsigned long division C or C55x assembly function (i.e., a 32 bit dividend and a 32-bit divisor, yielding a...

Hello all, I am looking for an unsigned long division C or C55x assembly function (i.e., a 32 bit dividend and a 32-bit divisor, yielding a 32-bit quotient) for a TI C5500 DSP. I would like to get a quotient data format of 16.16 (16 bits integer, 16 bits fractional) from a 32 bit dividend (uint) and 32-bit divisor (uint). Does anyone have a function that does this or something s...

## Need fastYUV to HSV colorspace conversion

inHi, I'm looking for a fast YUV to HSV colorspace conversion routine, preferable in fixed-point math. My target platform is a TI...

Hi, I'm looking for a fast YUV to HSV colorspace conversion routine, preferable in fixed-point math. My target platform is a TI C64x processor (fixed-point, no hardware divide...). Any pointers? Thanks. Chris N.

## Question on fixed point division

inHi all, I'm new to DSP programming. So far my asm program works fine on TI's TMS320LF2407 DSP. However, I have to extend my program and need...

Hi all, I'm new to DSP programming. So far my asm program works fine on TI's TMS320LF2407 DSP. However, I have to extend my program and need to divide two 10 bit integer numbers (a, b) which are not related to each other and change over time (they're obtained through 2 ch AD conversion). In most cases b > a. Does anyone know a simple algorithm to compute the result x = a/b? The DSP provid

## inverse matrix

inHi, I want to implement a Kalman-filter on a DSP56F8323. To do that I need to compute a matrix (9x9). Using Gauss-Jordan algorithmen I need to...

Hi, I want to implement a Kalman-filter on a DSP56F8323. To do that I need to compute a matrix (9x9). Using Gauss-Jordan algorithmen I need to divide a lot of figures. In my eyes there is a problem using fixed point arithmetics. Its not allowed to divide a smaller figure through a bigger one because the figure range is -1 to 0.999 and it would result in bigger than 1. I am DSP newby so it would...

## modeling tools

inHi, I am an R&D engineer that develops different types of modems. In the past I have used SPW and Matlab/Simulink for algorithm prototyping...

Hi, I am an R&D engineer that develops different types of modems. In the past I have used SPW and Matlab/Simulink for algorithm prototyping as well as fixed-point and bit-true modeling. These models were then provided to the engineering group ASIC implementation and then used for verification. I was wondering if I could get some expert opinions or discussion on experiences in similar ...

## Fixed IIR Filter Quality

inI have implemented a fixed point IIR filter and now comparing it against double precision implementation in simulink. I dont want to just...

I have implemented a fixed point IIR filter and now comparing it against double precision implementation in simulink. I dont want to just select 32 bits. I just want to have enough precision bits so thats its not unstable. What parameter do I use in order to measure the quality of the fixed point implemention? Is it the RMS on the difference between the two implementations? Mike Thi...

## Conversion to Fixed Point

inHi All, I am a novice to the business of Fixed Point. I have read various papers on implementation of Fixed Point and understood many concepts...

Hi All, I am a novice to the business of Fixed Point. I have read various papers on implementation of Fixed Point and understood many concepts but have a basic doubt in mind. Actually I am trying to convert an existing filter code available in floating point to fixed point. The program accepts floating point values from a data file and outputs a data file after filtering. I am wondering how t...

## 32 bit fixed point division

inHello All, Can anyone please help me in writing a C code for dividing a 32 bit fixed point number by another 32 bit number? I already have a...

Hello All, Can anyone please help me in writing a C code for dividing a 32 bit fixed point number by another 32 bit number? I already have a code which works fine for 16 bit (div_s) but it can not be converted to 32 bit. So please give me some source code or algorithm for implementing 32 bit division. Thanks and Regards, bd. This message was sent using the Comp.DSP web interface on...

## IIR filter problem

inHi Thanks for your answers. This is the problem... I'm building a IIR filter using fixed point, (well the limits are -1 to 1), I've...

Hi Thanks for your answers. This is the problem... I'm building a IIR filter using fixed point, (well the limits are -1 to 1), I've calculated the coeffs for the filter but there are values that are out of range of -1 to 1, for instance 4.5, or 2.8 etc... and other values that are in range for the same filter, for example 0.5, 0.126, etc .... Well I can't represent this 2 kind o...

## fixed point exp10(x)

inHello All, Can anyone please help me in implementing exp10(x) in a fixed point C. I need to convert a dB value ( 0 to 50 dB) to linear...

Hello All, Can anyone please help me in implementing exp10(x) in a fixed point C. I need to convert a dB value ( 0 to 50 dB) to linear domain value. This is for a 16-bit DSP application. Thanks and Regards, Patrick