SLLA613 august   2023 TUSB1146

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Test Description
    1. 2.1 Equalization Configuration
    2. 2.2 Eye Test
    3. 2.3 BER Test
    4. 2.4 Alternative BER Test
  6. 3Test Results
  7. 4Summary
  8. 5References

2.1 Equalization Configuration

The EQ method used by the TUSB1146 depends on the values written to the registers. These values can be controlled through I2C. The following is a summary about how to configure the TUSB1146 to use each EQ method with the provided register settings:

Static EQ:

  1. Ensure AEQ is disabled with AEQ_EN (0x1C bit 0 to 0)

  2. Enable the EQ_OVERRIDE (0xA bit 4 to 1) to enable I2C control of the registers and EQ level

  3. Set static EQ value to desired level with EQ1_SEL (0x20 bits 3:0)

The results provided in Section 3 used setting 8 for static EQ, which is approximately 11 dB at 5 GHz.

Fast AEQ:

  1. Enable AEQ with AEQ_EN (0x1C bit 0 to 1) and set AEQ_MODE (0x1C bits 2:1) to Fast (to 00)

  2. Enable the EQ_OVERRIDE to enable I2C control of the registers and EQ level

  3. Choose the long channel EQ value with LONG_EQ1 (0x1E bits 3:0)

  4. Choose the short channel EQ value with EQ1_SEL (0x20 bits 3:0)

  5. Enable the input signal, turn on the TUSB1146, and then reconnect the TX side cable to have the AEQ algorithm run

  6. Read the EQ value selected by AEQ with AEQ_STAT (0x3B bits 3:0)

The results provided in Section 3 used setting 1 for short channel and 15 for long channel, which is approximately 1.8 dB and 14 dB at 5 GHz, respectively.

Full AEQ:

  1. Enable AEQ with AEQ_EN (0x1C bit 0 to 1) and set AEQ_MODE (0x1C bits 2:1) to Full (to 01)

  2. Enable the input signal, turn on the TUSB1146, and then reconnect the TX side cable to have the AEQ algorithm run

  3. Read the EQ value selected by AEQ with AEQ_STAT (0x3B bits 3:0)

For more information about the registers and EQ methods, please see the TUSB1146 data sheet.