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 , TMS320F28P659DK-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

2.4.3.2 Trigger Bits

Trigger bits allow the CPU enable or disable logic in the tile or to trigger a specific action. For example, a receiver enable bit can be implemented to selectively enable or disable receive logic in the CLB at run time. These trigger bits can be implemented using the CLB_GP_REG register.

The CLB_GP_REG bits can be directly connected to the eight CLB tile inputs. The CPU can set any bit in the CLB_GP_REG to trigger an action in the CLB logic. For example, a receiver enable/disable bit can be implemented to enable or disable receive logic in the CLB at run-time. An example of an enable/disable bit implementaion is shown in the following code block. The code block uses C2000ware driverlib.

#define GPREG_ENABLE_RCVR           3U

void CCSI_HAL_enableClbReceiver()
{
    uint32_t gpRegVal = CLB_getGPREG(CCSI1_RX_TILE_BASE);

    // First check that receiver is in IDLE state
    while(HWREG(CCSI1_RX_TILE_BASE + CLB_LOGICCTL + CLB_O_DBG_OUT) &
            (CLB_DBG_OUT_FSM0_S1 | CLB_DBG_OUT_FSM0_S0)) {}

    // Enable receiver
    gpRegVal |= (1U << GPREG_ENABLE_RCVR);
    CLB_setGPREG(CCSI1_RX_TILE_BASE, gpRegVal);
}
void CCSI_HAL_disableClbReceiver()
{
    uint32_t gpRegVal = CLB_getGPREG(CCSI1_RX_TILE_BASE);

    // First check that receiver is in IDLE state
    while(HWREG(CCSI1_RX_TILE_BASE + CLB_LOGICCTL + CLB_O_DBG_OUT) &
            (CLB_DBG_OUT_FSM0_S1 | CLB_DBG_OUT_FSM0_S0)) {}

    // Disable receiver
    gpRegVal &= ~(1U << GPREG_ENABLE_RCVR);
    CLB_setGPREG(CCSI1_RX_TILE_BASE, gpRegVal);
}
Note: A CLB input must be dedicated to any CLB_GP_REG bit used in the logic design. Given that the number of CLB inputs is limited to eight, CLB_GP_REG bits should be used judiciously.