JAJSFM3E February   2015  – June 2018 LMH1218

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      SPI概略回路図
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Descriptions – SPI Mode/ Mode_SEL = 1 kΩ to VDD
    2.     Pin Descriptions – SMBUS Mode/ MODE_SEL = 1 kΩ to GND
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Recommended SMBus Interface AC Timing Specifications
    7. 7.7 Serial Parallel Interface (SPI) Bus Interface AC Timing Specifications
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Loss of Signal Detector
      2. 8.3.2 Continuous Time Linear Equalizer (CTLE)
      3. 8.3.3 2:1 Multiplexer
      4. 8.3.4 Clock and Data Recovery
      5. 8.3.5 Eye Opening Monitor (EOM)
      6. 8.3.6 Fast EOM
        1. 8.3.6.1 SMBus Fast EOM Operation
        2. 8.3.6.2 SPI Fast EOM Operation
      7. 8.3.7 LMH1218 Device Configuration
        1. 8.3.7.1 MODE_SEL
        2. 8.3.7.2 ENABLE
        3. 8.3.7.3 LOS_INT_N
        4. 8.3.7.4 LOCK
        5. 8.3.7.5 SMBus MODE
        6. 8.3.7.6 SMBus READ/WRITE Transaction
        7. 8.3.7.7 SPI Mode
          1. 8.3.7.7.1 SPI READ/WRITE Transaction
          2. 8.3.7.7.2 SPI Write Transaction Format
          3. 8.3.7.7.3 SPI Read Transaction Format
        8. 8.3.7.8 SPI Daisy Chain
          1. 8.3.7.8.1 SPI Daisy Chain Write Example
          2. 8.3.7.8.2 SPI Daisy Chain Write Read Example
            1. 8.3.7.8.2.1 SPI Daisy Chain Length of Daisy Chain Illustration
      8. 8.3.8 Power-On Reset
    4. 8.4 Device Functional Modes
    5. 8.5 Programming
    6. 8.6 Register Maps
      1. 8.6.1 Global Registers
      2. 8.6.2 Receiver Registers
      3. 8.6.3 CDR Registers
      4. 8.6.4 Transmitter Registers
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 General Guidance for All Applications
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Do's and Don'ts
    4. 9.4 Initialization Set Up
      1. 9.4.1 Selective Data Rate Lock
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Solder Profile
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 開発サポート
    2. 12.2 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13メカニカル、パッケージ、および注文情報

8.3.7.7.3 SPI Read Transaction Format

A SPI read transaction is 34 bits per device consisting of two 17 bits frames. The first 17-bit read transaction, first frame, shifts in the address to be read, followed by a dummy transaction, second frame, to shift out 17-bit read data. The R/W bit is 1 for the read transaction, as shown in Figure 17.

The first 17 bits from the read transaction specifies 1-bit of RW and 8-bits of address A7-A0 in the first 8 bits. The eight 1’s following the address are ignored. The second dummy transaction acts like a read operation on address 0xFF and needs to be ignored. However, the transaction is necessary in order to shift out the read data D7-D0 in the last 8 bits of the MISO output.

The signal timing for a SPI Read Transaction is shown in Figure 17. As with the SPI Write, the “prime” values on MISO during the first 16 clocks are a don’t-care for this portion of the transaction. Note, however, that the values shifted out on MISO during the last 17 clocks reflect the read address and 8-bit read data for the current transaction.

LMH1218 Fig_19_2_16.gifFigure 17. Signal Timing for a SPI Read Transaction