There is a lot of settings in the STlink Utility app - Option Bytes atc.
Doublecheck whether there is not something set such it is disturbing..
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- Mon Jan 27, 2020 10:28 pm
- Forum: General discussion
- Topic: [SOLVED]Interesting problem
- Replies: 46
- Views: 61567
- Mon Jan 27, 2020 9:24 pm
- Forum: General discussion
- Topic: ADC sample rate of 5 Ms/s on bluepill STM32F103
- Replies: 12
- Views: 24265
Re: ADC sample rate of 5 Ms/s on bluepill STM32F103
Below is a simulation of the input circuitry and Sample and Hold of STM32F103 ADC. Radc is 1k and Cadc is 8pF (Datasheet). C1 is a parasitic capacity of the input pin and wiring. Diodes and 200ohm resistor -> simplified PIN protection wiring inside the chip. 1. First picture is how the edges look li...
- Mon Jan 27, 2020 11:09 am
- Forum: General discussion
- Topic: ADC sample rate of 5 Ms/s on bluepill STM32F103
- Replies: 12
- Views: 24265
Re: ADC sample rate of 5 Ms/s on bluepill STM32F103
Even with 0ohm source the is an internal Radc and sampling capacitor Cadc.
Radc is usualy 1k-10k and Cadc 5-15pF (doublecheck the DS).
That limits the sampling rate, as you have to fully charge the Cadc via Rsource+Radc between the samples within the ADC input voltage limits.
Radc is usualy 1k-10k and Cadc 5-15pF (doublecheck the DS).
That limits the sampling rate, as you have to fully charge the Cadc via Rsource+Radc between the samples within the ADC input voltage limits.
- Sun Jan 26, 2020 9:54 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
This is provided by ARM: https://github.com/ARM-software/CMSIS_5/tree/5.5.1/CMSIS/DSP/Lib/GCC Damm ... ".a" files ==> Compiled libraries No source .. Well i'd prob not understand the "magic" anyway /Bingo https://github.com/ARM-software/CMSIS_5/tree/5.5.1/CMSIS/DSP/Source
- Sun Jan 26, 2020 6:44 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
Look at my above link - I did CMSIS FFT on 407, you may download sources of libraries for DSP and other math with FPU. https://www.st.com/content/st_com/en/products/embedded-software/mcu-mpu-embedded-software/stm32-embedded-software/stm32-standard-peripheral-libraries/stsw-stm32065.html#get-software...
- Sun Jan 26, 2020 6:33 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
Another argument for -Os is when you start experiments with those hw switches. With higher optimisation you may lose track.
- Sun Jan 26, 2020 6:23 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
A rather long thread on how we messed with stm32F407 FPU in 2017 https://web.archive.org/web/20170715084304/http://stm32duino.com/viewtopic.php?f=39&t=2001&sid=6ae2281d3c685a20709d7fc23d399868 There are some gcc settings recommended, like -mfloat-abi=hard -mfpu=fpv4-sp-d16 -fsingle-precision...
- Sun Jan 26, 2020 6:05 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
Hmm, most realistic results are with -Os, imho. With -2, -3, you are getting results which are off my understanding :) They indicate you have to be pretty careful with compilers because of optimization. Therefore Fortran is the only lanuage "approved" for whetstone, they say. Why to optimi...
- Sun Jan 26, 2020 5:36 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
Some reading on D and W
http://users.ece.utexas.edu/~ljohn/teac ... eicker.pdf
I would recommend to stay with -Os, as the higher levels may produce questionable results.
http://users.ece.utexas.edu/~ljohn/teac ... eicker.pdf
I would recommend to stay with -Os, as the higher levels may produce questionable results.
- Sun Jan 26, 2020 3:51 pm
- Forum: General discussion
- Topic: dhrystone and whetstone benchmarks
- Replies: 93
- Views: 67102
Re: dhrystone and whetstone benchmarks
@ag123: let us stay with dhrystone and whetstone in this thread..