SLYY211 October   2021 TMS320F2800132 , TMS320F2800133 , TMS320F2800135 , TMS320F2800137 , TMS320F2800152-Q1 , TMS320F2800153-Q1 , TMS320F2800154-Q1 , TMS320F2800155 , TMS320F2800155-Q1 , TMS320F2800156-Q1 , TMS320F2800157 , TMS320F2800157-Q1 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280033 , TMS320F280034 , TMS320F280034-Q1 , TMS320F280036-Q1 , TMS320F280036C-Q1 , TMS320F280037 , TMS320F280037-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038-Q1 , TMS320F280038C-Q1 , TMS320F280039 , TMS320F280039-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1. 1 Message from the editors
  2. 2 System Design
    1. 2.1 Control
      1. 2.1.1 Open loop versus closed loop
    2. 2.2 Feedback control
      1. 2.2.1 Error ratio
    3. 2.3 Dynamic systems
      1. 2.3.1 First order system
      2. 2.3.2 Second order system
    4. 2.4 System stability
      1. 2.4.1 Gain margin
      2. 2.4.2 Phase margin
    5. 2.5 Timing requirements
      1. 2.5.1 Peak/rise time
      2. 2.5.2 Settling time
      3. 2.5.3 Overshoot
      4. 2.5.4 Damping
      5. 2.5.5 Delay
    6. 2.6 Discrete Time Domain
    7. 2.7 Filters
      1. 2.7.1 Filter Types
      2. 2.7.2 Filter Orders
    8. 2.8 Notes
  3. 3 Controllers
    1. 3.1 Linear PID
    2. 3.2 Linear PI
    3. 3.3 Nonlinear PID
    4. 3.4 2P2Z
    5. 3.5 3P3Z
    6. 3.6 Direct form controllers
      1. 3.6.1 DF11
      2. 3.6.2 DF13
      3. 3.6.3 DF22
      4. 3.6.4 DF23
    7. 3.7 Notes
  4. 4 ADC
    1. 4.1 ADC definitions
    2. 4.2 ADC resolution
      1. 4.2.1 ADC resolution for unipolar
      2. 4.2.2 ADC resolution for differential signals
      3. 4.2.3 Resolution voltage vs. full-scale range
    3. 4.3 Quantization error of ADC
    4. 4.4 Total harmonic distortion (THD)
      1. 4.4.1 Total harmonic distortion (VRMS)
      2. 4.4.2 Total harmonic distortion (dBc)
    5. 4.5 AC signals
    6. 4.6 DC signals
    7. 4.7 Settling time and conversion accuracy
    8. 4.8 ADC system noise
    9. 4.9 Notes
  5. 5 Comparator
    1. 5.1 Basic operation
    2. 5.2 Offset and hysteresis
    3. 5.3 Propagation delay
    4. 5.4 Notes
  6. 6 Processing
    1. 6.1 Data representation
    2. 6.2 Central processing unit
      1. 6.2.1 CPU basics
      2. 6.2.2 CPU pipeline
      3. 6.2.3 Characteristics of a real-time processor
      4. 6.2.4 Signal chain
    3. 6.3 Memory
    4. 6.4 Direct memory access (DMA)
    5. 6.5 Interrupts
    6. 6.6 Co-processors and accelerators
    7. 6.7 Notes
  7. 7 Encoders
    1. 7.1 Encoder definitions
    2. 7.2 Types of encoders
    3. 7.3 Description of encoders
      1. 7.3.1 Linear encoders
      2. 7.3.2 Rotary encoders
      3. 7.3.3 Position encoders
      4. 7.3.4 Optical encoders
    4. 7.4 Absolute Vs incremental encoders
      1. 7.4.1 Absolute rotary encoders
      2. 7.4.2 Incremental encoders
    5. 7.5 Notes
  8. 8 Pulse width modulation (PWM)
    1. 8.1 PWM definitions
    2. 8.2 Duty cycle
    3. 8.3 Resolution
    4. 8.4 Deadband
    5. 8.5 Notes
  9. 9 DAC
    1. 9.1 DAC definitions
    2. 9.2 DAC error
      1. 9.2.1 DAC offset error
      2. 9.2.2 DAC gain error
      3. 9.2.3 DAC zero-code error
      4. 9.2.4 DAC full-scale error
      5. 9.2.5 DAC differential non-linearity (DNL)
      6. 9.2.6 DAC integral non-linearity (INL)
      7. 9.2.7 DAC total unadjusted error (TUE)
    3. 9.3 DAC output considerations
      1. 9.3.1 DAC linear range
      2. 9.3.2 DAC settling time
      3. 9.3.3 DAC load regulation
    4. 9.4 Notes
  10. 10Mathematical models
    1. 10.1 Laplace transforms
    2. 10.2 Transfer function
    3. 10.3 Transient response
    4. 10.4 Frequency response
    5. 10.5 Z-domain
    6. 10.6 Notes
  11. 11Important Notice

6.2.3 Characteristics of a real-time processor

Table 6-4 contains key characteristics that determine how good a processor is at performing a real-time control task. The term "fast" is used as a relative term to indicate the best performance possible. The execution speed of a complex task is determined by the number of CPU cycles needed to complete the constituent operations.

Table 6-4 Real-time control processor - characteristics.
Characteristic Description
Fast at performing math operations Math operations: MUL, ADD, SUB
Fast at trigonometric operations Trigonometric operations: SIN, COS, ATAN, DIV
Fast at saturation operations Saturation operations check for out of bounds conditions and if detected the value is clamped or saturated
Contains deterministic execution A real-time control application has a fixed amount of time to execute algorithms, and if the time taken to perform the algorithms is deterministic (or known) it is easier to budget the available MIPS
Fast access to peripheral registers For example, reading sensor inputs (example: ADC) and writing to output registers (example: EPWM)
Fast Interrupt Response The processor needs to respond to periodic interrupt events with low latency to satisfy real time deadlines
Floating-point operation capability Floating-point operations are generally easier to use which make the control algorithms more robust
32-bit and 64-bit data precision A processor that can be scaled in precision based on the application is ideal
Multicore Support Having dual cores or more helps increase the amount of tasks that are executed given a specified amount of time