SPRAC77E January   2022  – February 2022 TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1.   Trademarks
  2. 1Introduction
  3. 2PTO – PulseGen
    1. 2.1 PulseGen Implementation Overview
    2. 2.2 PulseGen Limitations
    3. 2.3 PulseGen CLB Configuration
    4. 2.4 PulseGen Input and Output Signals
  4. 3PTO – QepDiv
    1. 3.1 QepDiv Implementation Overview
    2. 3.2 QepDiv Limitations
    3. 3.3 QepDiv Divider Settings and Initialization
    4. 3.4 QepDiv CLB Configuration
  5. 4PTO – Abs2Qep
    1. 4.1 Abs2Qep Chip resources
    2. 4.2 Abs2Qep Theory of Operation
      1. 4.2.1 Abs2Qep Translation Equations
      2. 4.2.2 Abs2Qep Translation Example
      3. 4.2.3 Abs2Qep Zero Cross Detection
    3. 4.3 Abs2Qep CLB Configuration
      1. 4.3.1 Abs2Qep QEP-A/B Pulse Train Generation
      2. 4.3.2 Abs2Qep Halt Latch
      3. 4.3.3 Abs2Qep High Level Controller (HLC)
    4. 4.4 Abs2Qep Input and Output Signals
  6. 5PTO – QepOnClb QEP Decoder
    1. 5.1 QepOnClb and eQEP Comparison
    2. 5.2 QepOnClb Chip resources
    3. 5.3 QepOnClb Theory of Operation
    4. 5.4 QepOnClb CLB Resources
      1. 5.4.1 QepOnClb QCLK State Machine
      2. 5.4.2 QepOnClb Direction Decode
      3. 5.4.3 QepOnClb Error Detection
      4. 5.4.4 QepOnClb Simulation Waveforms
  7. 6Example Projects
    1. 6.1 Hardware Requirements
    2. 6.2 Installing Code Composer Studio and C2000WARE-MOTORCONTROL-SDK™
    3. 6.3 Import and Run Example Project
    4. 6.4 PulseGen Example
    5. 6.5 QepDiv Example
    6. 6.6 Abs2Qep Example
      1. 6.6.1 Watch Variables
      2. 6.6.2 Test Signals
      3. 6.6.3 Pin Usage and Test Connections
    7. 6.7 QepOnClb Example
      1. 6.7.1 Watch Variables
      2. 6.7.2 Header Pin Connections
  8. 7Library Source and Projects
    1. 7.1 Locating the Library Source Code
    2. 7.2 Import and Build the Library Project
    3. 7.3 PTO - PulseGen API
      1. 7.3.1 pto_pulsegen_runPulseGen
      2. 7.3.2 pto_startOperation
      3. 7.3.3 pto_pulsegen_setupPeriph
      4. 7.3.4 pto_pulsegen_reset
    4. 7.4 PTO - QepDiv API
      1. 7.4.1 pto_qepdiv_config
      2. 7.4.2 pto_startOperation
      3. 7.4.3 pto_qepdiv_setupPeriph
      4. 7.4.4 pto_qepdiv_reset
    5. 7.5 PTO - Abs2Qep API
      1. 7.5.1 Abs2Qep API Configuration
      2. 7.5.2 pto_abs2qep_runPulseGen
      3. 7.5.3 pto_abs2qep_setupPeriph
      4. 7.5.4 pto_abs2qep_translatePosition
    6. 7.6 PTO - QepOnClb API
      1. 7.6.1 pto_qeponclb_setupPeriph
      2. 7.6.2 pto_qeponclb_initCLBQEP
      3. 7.6.3 pto_qeponclb_configMaxCounterPos
      4. 7.6.4 pto_qeponclb_enableCLBQEP
      5. 7.6.5 pto_qeponclb_resetCLBQEP
      6. 7.6.6 pto_qeponclb_getCounterVal
      7. 7.6.7 pto_qeponclb_getCLBQEPPos
      8. 7.6.8 pto_qeponclb_clearFIFOptr
  9. 8Using the Reference APIs in Projects
    1. 8.1 Adding PTO Support to a Project
    2. 8.2 Routing To and From the CLB
    3. 8.3 Initialization Steps
      1. 8.3.1 PTO-PulseGen API Initalization
      2. 8.3.2 PTO-QepDiv API Initialization
      3. 8.3.3 PTO-Abs2Qep API Initialization
      4. 8.3.4 PTO-QepOnClb API Initialization
  10. 9References
  11.   Revision History

4.3.1 Abs2Qep QEP-A/B Pulse Train Generation

The QEP-A and QEP-B signal are generated by a finite state machine (FSM). The state diagrams are shown in Figure 4-8 and have the following characteristics:

  • A state transition occurs when QCLK = 1.
  • The state remains the same when QCLK = 0
  • Only one QEP signal changes at a time
  • Which signal transitions first depends on the direction input from the C28x.

Figure 4-8 Abs2Qep PTO State Diagrams

Table 4-4 and Table 4-5 are the corresponding Karnaugh Maps. The resulting equations are determined by inspecting each "1" within the map or by using a Karnaugh Map solver. x is used to indicate states which are not valid. Note that there is no need to further simplify the equations; they can be entered into the CLB tool as shown. Use the OR operator to build up the full equation from the parts as shown in the simulation results (Figure 4-9).

Table 4-4 QEP-A (s0) Signal Generation Karnaugh Maps
DIRECTION (e0) = 1 (Forward)
Next State
QCLK, QEP-B (e1, s1)		 DIRECTION (e0) = 0 (Reverse)
Next State
QCLK, QEP-B (e1, s1)
00 01 11 10 00 01 11 10
Current State
s0, s1
(QEP-A, B)		 00 0 0 x (2) 1 (2) Current State
s0, s1
(QEP-A, B)		 00 0 0 0 x
01 0 0 x 0 01 0 0 1 (3) x (3)
11 1 (1) 1 (1) 0 x 11 1 (1) 1 (1) x (3) 1 (3)
10 1 (1) 1 (1) 1(2) x (2) 10 1 (1) 1 (1) x 0
(1) s0_1 = (e0 & s0 & !e1) | (!e0 & s0 & !e1) = s0 & !e1
(2) s0_2 = e0 & !s1 & e1
(3) s0_3 = !e0 & s1 & e1
Table 4-5 QEP-B (s1) Signal Generation Karnaugh Maps
DIRECTION (e0) = 1 (Forward)
Next State
QCLK, QEP-A (e1, s0)		 DIRECTION (e0) = 0 (Reverse)
Next State
QCLK, QEP-A (e1, s0)
00 01 11 10 00 01 11 10
Current State
s0, s1
(QEP-A, B)		 00 0 0 0 x Current State
s0, s1
(QEP-A, B)		 00 0 0 x (3) 1 (3)
01 1 (1) 1 (1) x 0 01 1 (1) 1 (1) 1 (3) x (3)
11 1 (1) 1 (1) x (2) 1 (2) 11 1 (1) 1 (1) 0 x
10 0 0 1 (2) x (2) 10 0 0 x 0
(1) s1_1 = (e0 & s1 & !e1) | (!e0 & s1 & e1) = s1 & !e1
(2) s1_2 = e0 & s0 & e1
(3) s1_3 = !e0 & !s0 & e1

Figure 4-9 shows the SystemC simulation results.

GUID-20210319-CA0I-69SL-ZXBP-NPFJZBRPMPXG-low.png Figure 4-9 Simulation QEP-A and QEP-B Generation