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1 vote
2 answers
210 views

Dealing with denorms in the ARM Cortex M4 FPU

Okay, a year ago I asked this other question and got zero responses. Now, I will try to get a little more specific: The ARM chip that is in this product is the STM32F407 and I got the docs on that ...
robert bristow-johnson's user avatar
4 votes
1 answer
3k views

ARM Cortex-M Floating Point Multiply-Accumulate Cycle Time

According to the ARM Cortex M4 technical manual, a floating point multiply accumulate instruction (VMLA.F32) takes 3 cycles. However the separate multiply (VMUL.F32) and add (VADD.F32) instructions ...
Jon's user avatar
  • 5,117
2 votes
1 answer
409 views

How does the ARM Compiler (Version 5) handle double-precision floats in devices whose floating-point unit hardware only supports single precision?

After reading ARM Compiler version 5's manual, it says that for devices without a floating point unit, floats are dealt with through software implementations, which is likely going to be slower than ...
a2xia's user avatar
  • 135
0 votes
1 answer
1k views

How can I save a floating point value to a Microcontroller data Flash

I'm trying to save some floating values to the Data flash of my Nuc220(ARM-M0 32 bit) Microcontroller using ISP procedure. ...
Arun Joe Cheriyan's user avatar
2 votes
2 answers
3k views

STM32 NaN value for floating point operations on global variables

I am trying to implement a simple Odometry computation loop. Which is being run in a while loop. Following is the code: ...
Asusrog's user avatar
  • 85
3 votes
1 answer
11k views

How many cycles does an ARM Cortex M0 use to multiply floats?

On an ARM cortex m0+: How many cycles does it take to perform multiplication of single precision floats and store them into a float? i.e. x = a*b; Where x, a, and b are single precision IEEE 754 ...
hassan789's user avatar
  • 2,116
1 vote
0 answers
315 views

Float calculations hangs on Kinetis K20 (arm-m4-no-fpu) when PWM interrupt is on

I will use this ARM to control Induction Motor with three-phase inverter. When the program encounters any float operations, like simple plus operation, the system hangs but the pause of debug works ...
user avatar
5 votes
1 answer
2k views

Cortex-M4F FPU problems

I'm writing some code for a Texas Instruments Stellaris Launchpad board (a Cortex-M4F, the chip is a LM4F120H5QR). I'm using the IRMP library for infrared decoding, which works fine, as long as I don'...
AVH's user avatar
  • 151