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

6.5.3.6 OVERDRIVE SKIP ROM Command [3Ch]

The TMF0020 supports a high-speed mode called the Overdrive mode. The OVERDRIVE SKIP ROM command sequence starts with the host generating the RESET pulse of at least 480μs. The TMF0020 responds with a PRESENCE pulse. Next, the host continues by issuing the OVERDRIVE SKIP ROM command, 3Ch, in standard speed. The device now enters Overdrive mode. Make sure all subsequent communication with the target device is at overdrive speed. The host can bring all the target devices back to standard speed by issuing a reset pulse of at least 480μs.

If the OVERDRIVE SKIP ROM command is issued when there are multiple targets on the SDQ single-wire serial interface bus, all the target devices enter Overdrive mode. All subsequent communication addresses a specific device. This procedure is initiated by issuing a reset pulse at overdrive speed followed by an OVERDRIVE MATCH ROM or SEARCH ROM command sequence. This speeds up the time for the search process. If the OVERDRIVE SKIP ROM command issues when there are multiple targets on the SDQ single-wire serial interface bus, all the targets begin responding to the subsequent memory command resulting in a bus data collision.