Chandra
Guest
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 Posted:
Fri Dec 23, 2005 4:13 pm Post subject:
ADSP21262 coding problem |
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Hi All,
I have got two queries ...
(a) can anyone tell me that how to create a .LDF for mixed coding
(assemble and C) ? If i use default 21262_asm.LDF given with VDSP 4.0
++ , ccall() is not working and when i use 21262_C.LDF the interrupt
is a problem. I am trying to call a C function to perform FFT from
assembly . Any example code will be very helpful.
(b) when i try calculating FFT using assembly subroutine with a fixed
input, everything works fine , but when i take input of ADC in real
time , the output of fft becomes 0xFFFFFFF . Whereas the input buffer
plot shows that acquisition is proper. There is no problem in
acquisition . Kindly guide.
Thanks,
chandra |
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Jim Thomas
Guest
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| Posted:
Fri Dec 23, 2005 5:16 pm Post subject:
Re: ADSP21262 coding problem |
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Chandra wrote:
| Quote: | Hi All,
I have got two queries ...
(a) can anyone tell me that how to create a .LDF for mixed coding
(assemble and C) ? If i use default 21262_asm.LDF given with VDSP 4.0
++ , ccall() is not working and when i use 21262_C.LDF the interrupt
is a problem. I am trying to call a C function to perform FFT from
assembly . Any example code will be very helpful.
|
If you're going to use C, stick with 21262_C.LDF. What sort of problems
are you having with interrupts?
In general, it's a lot easier to call an assembly program from C than it
is to call a C program from assembly. Without knowing what you're
trying to do, I suggest that you restructure your interrupt routine so
that its overall structure and logic is written in C, but the sample
processing is done in C-callable assembly functions.
| Quote: |
(b) when i try calculating FFT using assembly subroutine with a fixed
input, everything works fine , but when i take input of ADC in real
time , the output of fft becomes 0xFFFFFFF . Whereas the input buffer
plot shows that acquisition is proper. There is no problem in
acquisition . Kindly guide.
|
My guess is that the format of the input data is not what the FFT expects.
--
Jim Thomas Principal Applications Engineer Bittware, Inc
jthomas@bittware.com http://www.bittware.com (603) 226-0404 x536
I thought I was wrong once, but I was mistaken. |
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