SPRAD62 February   2023 TMS320F280023C , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280037C , TMS320F280037C-Q1 , TMS320F280038C-Q1 , TMS320F280039C , TMS320F280039C-Q1 , TMS320F28386D , TMS320F28386D-Q1 , TMS320F28386S , TMS320F28386S-Q1 , TMS320F28388D , TMS320F28388S , TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Serial Port Design Methodology
    1. 2.1 Step 1: Understand Design Requirements
    2. 2.2 Step 2: Identify Required Inputs to the CLB Tile
      1. 2.2.1 GPIO Input Qualification
      2. 2.2.2 CLB Input Settings
    3. 2.3 Step 3: Identify Required Outputs from CLB Logic
      1. 2.3.1 Synchronizing Outputs Signals
      2. 2.3.2 Output Signal Conditioning
    4. 2.4 Step 4: Design the CLB Logic
      1. 2.4.1 Resource Allocation
      2. 2.4.2 Exchanging Data Between CLB FIFOs and MCU RAM
      3. 2.4.3 CLB Logic Status and Trigger Flags
        1. 2.4.3.1 Status/Flag Bits
        2. 2.4.3.2 Trigger Bits
    5. 2.5 Step 5: Simulate the Logic Design
    6. 2.6 Step 6: Test the CLB Logic
  5. 3Example A: Using the CLB to Input and Output a TDM Stream in Audio Applications
    1. 3.1 Example Overview
    2. 3.2 Step 1: Understand Design Requirements
    3. 3.3 Step 2: Identify Required Inputs to the CLB Tile
    4. 3.4 Step 3: Identify Required Outputs from CLB Logic
    5. 3.5 Step 4: Design the CLB Logic
      1. 3.5.1 Resource Allocation
      2. 3.5.2 TDM Word Counter
      3. 3.5.3 FSYNC and DATA1 Output Synchronization
    6. 3.6 Step 5: Simulate the Logic Design
    7. 3.7 Step 6: Test the CLB Logic
      1. 3.7.1 Hardware Setup and Connections
      2. 3.7.2 Software Setup
      3. 3.7.3 Testing Output Setup and Hold Times
      4. 3.7.4 Testing Data Integrity
  6. 4Example B: Using the CLB to Implement a Custom Communication Bus for LED Driver in Lighting Applications
    1. 4.1 Example Overview
    2. 4.2 Step 1: Understand Design Requirements
    3. 4.3 Step 2: Identify Required Inputs to the CLB Tile
    4. 4.4 Step 3: Identify Required Outputs From CLB Logic
    5. 4.5 Step 4: Design the CLB Logic
      1. 4.5.1 TX Tile Logic
      2. 4.5.2 RX Tile Logic
      3. 4.5.3 Data Clocking
    6. 4.6 Step 5: Simulate the Logic Design
    7. 4.7 Step 6: Test the CLB Logic
      1. 4.7.1 Hardware Setup and Connections
      2. 4.7.2 Software Setup
      3. 4.7.3 Testing Output Setup and Hold Times
  7. 5References

4.2 Step 1: Understand Design Requirements

The design parameters used for this demo are listed in Table 4-1.

Table 4-1 Design Requirements
Design Parameter Value
Display module size 16 x 16 RGB LEDs
Frame rate 60 Hz
Refresh rate 7680 Hz
PWM resolution 16 bits
Cascaded devices 1 (can be increased to 2)
CCSI bus count 1
SCLK frequency 5.0 MHz
GCLK frequency 70.0 MHz
TSW 643 ns

The CCSI bus protocol supported by the LP5891-Q1 LED driver device is shown in Figure 4-2. The CCSI protocol includes the following requirements:

  • Continuous serial clock
  • Variable frame lengths with start, idle, data, and end states
  • 16-bit head and data words
  • Check-bit appended on all head and data words
Figure 4-2 CCSI Frame

Two additional requirements are added. First, configurable single and dual clock-edge transmission and reception is required to support different LED driver devices. For example, the TLC6983 LED display driver uses dual clock-edge data transmission and reception. Second, the ability to generate simultaneous VSYNC commands on multiple CCSI buses is desired. The VSYNC is used to sync the display of each frame for the devices in a cascaded chain.