- Bit Timing Calculator for CAN FD :: kvaser
- CAN Bus Bit Timing Calculator :: kvaser
- CAN Bit Time Calculation :: bittiming
- STM32G4 FDCAN :: Create by : phryniszak
All algorithms is tested on those site`s
- calulate0 - Brute Force Method - The most difficult method!!!! Use only when all methods have failed
- calculate1
- calculate2
- calculate3
- calculate4
- calulate0 - 16777216
- calculate1 - 1912
- calculate2 - 32768
- calculate3 - 39066
- calculate4 - 511
- This test shows how many calculations were performed by different algorithms with the same input data.
- calculate4_can - This method is based on calculate4 that is, in terms of speed it is the same. "Benchmark = calculate4 = 511"
- calculate4_fdcan - This method is called twice calculate4, meaning it calculates the divisors for the head speed and the data separately. "Benchmark = calculate4 * 2 = 511 * 2 = 1022"
- Qt in .pro file: DEFINES += CANSOLVER_TEST=1 CANSOLVER_PRINT=1 CANSOLVER_MINIMUM=0
- Eclipse: need add preprocessor variables to: compiler settings/preprocessor CANSOLVER_TEST=1 CANSOLVER_PRINT=1 CANSOLVER_MINIMUM=0
- CMake: add_definitions(-DCANSOLVER_PRINT=1 -DCANSOLVER_TEST=1 -DCANSOLVER_MINIMUM=0)
- clang: g++ -DCANSOLVER_PRINT=1 -DCANSOLVER_TEST=1 -DCANSOLVER_MINIMUM=0
- Microcontroller: nothing to add, all hard function is disabled
struct Result {
u32 bitrate; // result bit rate [bit/sec]
u32 prescaler; // The clock prescaler value used for generating the CAN timing.
u32 tq_per_bit; // Number of Time Quanta (TQ) per bit in the CAN bit timing.
u32 tBS1; // Time Segment 1 (in TQ), which includes Propagation and Phase Segment 1.
u32 tBS2; // Time Segment 2 (in TQ), used for Phase Segment 2.
u32 sync_jump_width; // Synchronization Jump Width (SJW) in TQ, defining the maximum adjustment for resynchronization.
float sample_point; // The sample point location as a percentage [%] of the bit period.
float freq_diff; // The frequency deviation [%] between the calculated and desired bit rate.
bool solutionFinded; // Solution finded indicator (only the best structure)
// Class method for comparison
bool operator==(const Result& other) const {
// Compare all fields to determine equality between two results.
return std::tie(prescaler, tq_per_bit, tBS1, tBS2, sync_jump_width, sample_point, freq_diff) ==
std::tie(other.prescaler, other.tq_per_bit, other.tBS1, other.tBS2, other.sync_jump_width, other.sample_point, other.freq_diff);
}
};
struct Input {
u32 clock; // The FDCAN peripheral's input clock frequency in Hz.
u32 clock_divider; // Divider applied to the input clock to determine the CAN clock frequency.
u32 rate; // Desired nominal bit rate in bits per second (bps).
float sampling_point_min; // Minimum allowed sampling point percentage [%] (0–100).
float sampling_point_max; // Maximum allowed sampling point percentage [%] (0–100).
u32 prescaler_min; // Minimum value of the prescaler for clock division.
u32 prescaler_max; // Maximum value of the prescaler for clock division.
u32 time_seg1_min; // Minimum duration of Time Segment 1 in Time Quanta (TQ).
u32 time_seg1_max; // Maximum duration of Time Segment 1 in Time Quanta (TQ).
u32 time_seg2_min; // Minimum duration of Time Segment 2 in Time Quanta (TQ).
u32 time_seg2_max; // Maximum duration of Time Segment 2 in Time Quanta (TQ).
u32 sjw_min; // Minimum Synchronization Jump Width (SJW) in Time Quanta (TQ).
u32 sjw_max; // Maximum Synchronization Jump Width (SJW) in Time Quanta (TQ).
float baudrate_tolerance = 1.0f; // Allowed tolerance for the deviation of the actual bit rate from the desired rate, in percent.
};
/*
* Brute Force Method - The most difficult method!!!! Use only when all methods have failed
* Estimated cost = (prescaler_max - prescaler_min) * (time_seg1_max - time_seg1_min) * (time_seg2_max - time_seg2_min)
* From Shpegun60
*/
const Result& calculate0(const Input& in);
/*
* Estimated cost = (prescaler_max - prescaler_min) * (sampling_point_min - sampling_point_max) / 0.1 --> FAST
* from https://github.com/phryniszak/stm32g-fdcan
*/
const Result& calculate1(const Input& in); // Computes all possible CAN timing configurations based on the input parameters.
/*
* Estimated cost = (time_seg1_max - time_seg1_min) * (time_seg2_max - time_seg2_min)
*
* from https://github.com/waszil/can_bit_timing_calculator/tree/master
*/
const Result& calculate2(const Input& in); // Computes all possible CAN timing configurations based on the input parameters.
/*
* Estimated cost = ???
* from https://github.com/rhyttr/SocketCAN/blob/master/can-utils/can-calc-bit-timing.c
*/
const Result& calculate3(const Input& in); // Computes all possible CAN timing configurations based on the input parameters.
/*
* Estimated cost = ??? ULTRA - FAST
* from https://github.com/shpegun60/MCP251XFD/blob/master/Core/MCP251XFD/MCP251XFD.c
*/
const Result& calculate4(const Input &in);
/*
* Methods for microcontrollers (based on calculate4)
*/
inline static Result calculate4_can(const Input &head);
inline static std::array<Result, 2> calculate4_fdcan(const Input &head, const Input &data);void CanSolver::test()
{
CanSolver nom;
CanSolver::Input nominal {
100000000, // clock
1, // clock_divider
1000000, // rate
75, // sampling_point_min
80, // sampling_point_max
1, // prescaler_min
512, // prescaler_max
1, // time_seg1_min
256, // time_seg1_max
1, // time_seg2_min
128, // time_seg2_max
1, // sjw_min
128, // sjw_max
0.1f // baudrate_tolerance
};
// CanSolver::Input nominal {
// 100000000, // clock
// 1, // clock_divider
// 2500000, // rate
// 75, // sampling_point_min
// 80, // sampling_point_max
// 1, // prescaler_min
// 32, // prescaler_max
// 1, // time_seg1_min
// 32, // time_seg1_max
// 1, // time_seg2_min
// 16, // time_seg2_max
// 1, // sjw_min
// 16, // sjw_max
// 0.1f // baudrate_tolerance
// };
{
nom.calculate0(nominal);
nom.remove_duplicates();
nom.sort();
std::cout << "Results for Brute Force Method:\n";
nom.print_results();
std::cout << "Benchmark: " << nom.getBenchmark() << "\n";
std::cout << "\n";
}
{
nom.calculate1(nominal);
nom.remove_duplicates();
nom.sort();
std::cout << "Results for First Method:\n";
nom.print_results();
std::cout << "Benchmark: " << nom.getBenchmark() << "\n";
std::cout << "\n";
}
{
nom.calculate2(nominal);
nom.remove_duplicates();
nom.sort();
std::cout << "Results for Second Algititm:\n";
nom.print_results();
std::cout << "Benchmark: " << nom.getBenchmark() << "\n";
std::cout << "\n";
}
{
nom.calculate3(nominal);
nom.remove_duplicates();
nom.sort();
std::cout << "Results for Third Algititm:\n";
nom.print_results();
std::cout << "Benchmark: " << nom.getBenchmark() << "\n";
std::cout << "\n";
}
{
nom.calculate4(nominal);
nom.remove_duplicates();
nom.sort();
std::cout << "Results for Four Algititm:\n";
nom.print_results();
std::cout << "Benchmark: " << nom.getBenchmark() << "\n";
std::cout << "\n";
}
{
std::cout << "Results for Simple CAN:\n";
CanSolver can;
auto res = CanSolver::calculate4_can(nominal);
can.print_results(res);
std::cout << "\nPassed: "<< (nom.getBest() == res) << "\n\n";
}
{
std::cout << "Results for FDCAN:\n";
CanSolver can;
auto res = CanSolver::calculate4_fdcan(nominal, nominal);
can.print_results(res[0]);
can.print_results(res[1]);
std::cout << "\nHead Passed: "<< (nom.getBest() == res[0]) << "\n";
std::cout << "Data Passed: "<< (nom.getBest() == res[1]) << "\n\n";
}
}Results for Brute Force Method:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
1 | 25 | 4 | 2 | 1 | 1 | 75 | 0
1 | 5 | 20 | 14 | 5 | 5 | 75 | 0
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
1 | 4 | 25 | 18 | 6 | 6 | 76 | 0
1 | 2 | 50 | 37 | 12 | 12 | 76 | 0
1 | 1 | 100 | 75 | 24 | 24 | 76 | 0
1 | 1 | 100 | 76 | 23 | 23 | 77 | 0
1 | 2 | 50 | 38 | 11 | 11 | 78 | 0
1 | 1 | 100 | 77 | 22 | 22 | 78 | 0
1 | 1 | 100 | 78 | 21 | 21 | 79 | 0
1 | 20 | 5 | 3 | 1 | 1 | 80 | 0
1 | 10 | 10 | 7 | 2 | 2 | 80 | 0
1 | 5 | 20 | 15 | 4 | 4 | 80 | 0
1 | 4 | 25 | 19 | 5 | 5 | 80 | 0
1 | 2 | 50 | 39 | 10 | 10 | 80 | 0
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
------
The best:
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
Benchmark: 16777216
Results for First Method:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
1 | 25 | 4 | 2 | 1 | 1 | 75 | 0
1 | 5 | 20 | 14 | 5 | 5 | 75 | 0
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
1 | 4 | 25 | 18 | 6 | 6 | 76 | 0
1 | 2 | 50 | 37 | 12 | 12 | 76 | 0
1 | 1 | 100 | 75 | 24 | 24 | 76 | 0
1 | 1 | 100 | 76 | 23 | 23 | 77 | 0
1 | 2 | 50 | 38 | 11 | 11 | 78 | 0
1 | 1 | 100 | 77 | 22 | 22 | 78 | 0
1 | 1 | 100 | 78 | 21 | 21 | 79 | 0
1 | 20 | 5 | 3 | 1 | 1 | 80 | 0
1 | 10 | 10 | 7 | 2 | 2 | 80 | 0
1 | 5 | 20 | 15 | 4 | 4 | 80 | 0
1 | 4 | 25 | 19 | 5 | 5 | 80 | 0
1 | 2 | 50 | 39 | 10 | 10 | 80 | 0
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
------
The best:
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
Benchmark: 1912
Results for Second Algititm:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
1 | 25 | 4 | 2 | 1 | 1 | 75 | 0
1 | 5 | 20 | 14 | 5 | 5 | 75 | 0
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
1 | 4 | 25 | 18 | 6 | 6 | 76 | 0
1 | 2 | 50 | 37 | 12 | 12 | 76 | 0
1 | 1 | 100 | 75 | 24 | 24 | 76 | 0
1 | 1 | 100 | 76 | 23 | 23 | 77 | 0
1 | 2 | 50 | 38 | 11 | 11 | 78 | 0
1 | 1 | 100 | 77 | 22 | 22 | 78 | 0
1 | 1 | 100 | 78 | 21 | 21 |79 | 0
1 | 20 | 5 | 3 | 1 | 1 | 80 | 0
1 | 10 | 10 | 7 | 2 | 2 | 80 | 0
1 | 5 | 20 | 15 | 4 | 4 | 80 | 0
1 | 4 | 25 | 19 | 5 | 5 | 80 | 0
1 | 2 | 50 | 39 | 10 | 10 | 80 | 0
1 | 1 |100 | 79 | 20 | 20 | 80 | 0
------
The best:
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
Benchmark: 32768
Results for Third Algititm:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
1 | 25 | 4 | 2 | 1 | 1 | 75 | 0
1 | 5 | 20 | 14 | 5 | 5 | 75 | 0
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
1 | 4 | 25 | 18 | 6 | 6 | 76 | 0
1 | 2 | 50 | 37 | 12 | 12 | 76 | 0
1 | 1 | 100 | 75 | 24 | 24 | 76 | 0
1 | 1 | 100 | 76 | 23 | 23 | 77 | 0
1 | 2 | 50 | 38 | 11 | 11 | 78 | 0
1 | 1 | 100 | 77 | 22 | 22 | 78 | 0
1 | 1 | 100 | 78 | 21 | 21 | 79 | 0
1 | 20 | 5 | 3 | 1 | 1 | 80 | 0
1 | 10 | 10 | 7 | 2 | 2 | 80 | 0
1 | 5 | 20 | 15 | 4 | 4 | 80 | 0
1 | 4 | 25 | 19 | 5 | 5 | 80 | 0
1 | 2 | 50 | 39 | 10 | 10 | 80 | 0
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
------
The best:
1 | 1 | 100 | 74 | 25 | 25 | 75 | 0
Benchmark: 39066
Results for Four Algititm:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
1 | 25 | 4 | 2 | 1 | 1 | 75 | 0
1 | 20 | 5 | 3 | 1 | 1 | 80 | 0
1 | 10 | 10 | 7 | 2 | 2 | 80 | 0
1 | 5 | 20 | 15 | 4 | 4 | 80 | 0
1 | 4 | 25 | 19 | 5 | 5 | 80 | 0
1 | 2 | 50 | 39 | 10 | 10 | 80 | 0
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
------
The best:
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
Benchmark: 511
Results for Simple CAN:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
------
The best:
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
Passed: 1
Results for FDCAN:
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
------
The best:
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
Rate[Mb]| Prescaler | TQ/bit | TimeSeg1 | TimeSeg2 | SJW | SampleP[%] | Diff[%]
-------------------------------------------------------------------------------
------
The best:
1 | 1 | 100 | 79 | 20 | 20 | 80 | 0
Head Passed: 1
Data Passed: 1
Process exited with code: 0