SLVSJQ4 May   2026 TMF0020

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Functional Tests
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 20480-Bit FRAM
      2. 6.3.2 FRAM Status Memory
      3. 6.3.3 Address Registers and Transfer Status
      4. 6.3.4 Writing Data to the FRAM
      5. 6.3.5 TMF0020 Device ID
      6. 6.3.6 Bus Termination
    4. 6.4 Device Functional Modes
      1. 6.4.1 Test Procedures for Functional Tests
        1. 6.4.1.1 Multiple Target Configurations
    5. 6.5 Programming
      1. 6.5.1 Serial Communication
      2. 6.5.2 Initialization
      3. 6.5.3 ROM Commands
        1. 6.5.3.1 READ ROM Command [33h]
        2. 6.5.3.2 MATCH ROM Command [55h]
        3. 6.5.3.3 SKIP ROM Command [CCh]
        4. 6.5.3.4 SEARCH ROM Command [F0h]
        5. 6.5.3.5 RESUME Command [A5h]
        6. 6.5.3.6 OVERDRIVE SKIP ROM Command [3Ch]
        7. 6.5.3.7 OVERDRIVE MATCH ROM Command [69h]
      4. 6.5.4 Memory Function Commands
        1. 6.5.4.1 Write Scratchpad Command [0Fh]
        2. 6.5.4.2 Read Scratchpad Command [AAh]
        3. 6.5.4.3 Copy Scratchpad [55h]
        4. 6.5.4.4 Read Memory [F0h]
        5. 6.5.4.5 Extended Read Memory [A5h]
        6. 6.5.4.6 Memory Command Flow Charts
      5. 6.5.5 SDQ single-wire serial interface Signaling
        1. 6.5.5.1 RESET and PRESENCE PULSE
        2. 6.5.5.2 Write-Read-Time Slots
      6. 6.5.6 IDLE
      7. 6.5.7 CRC Generation
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Packaging Information
    2. 10.2 Tape and Reel Information

7.2.2 Detailed Design Procedure

Implementing the SDQ single-wire serial interface host using bit-banging over GPIO is possible. In this case, consider additional error checking for the reset routine of the TMF0020 to verify that the target operates as expected on the bus.

Whenever the host sends a reset, the target devices acknowledge the reset with a presence pulse. Before the presence pulse, the host must confirm that the bus releases and returns to a high level, indicating that nothing is holding the bus unexpectedly low. As the minimum tPDH is 15μs, the host look for a logic high on the bus 10μs after releasing the bus at the end of the reset is sufficient to confirm the bus released for the target devices to acknowledge.