ZHCSKF3B April 2017 – October 2019 LMH0397
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 說明 （續）
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 4-Level Input Pins and Thresholds
- 8.3.2 Equalizer (EQ) and Cable Driver (CD) Mode Control
- 8.3.3 Input Carrier Detect
- 8.3.4 –6-dB Splitter Mode Launch Amplitude for SDI_IO+ (EQ Mode Only)
- 8.3.5 Continuous Time Linear Equalizer (CTLE)
- 8.3.6 Clock and Data (CDR) Recovery
- 8.3.7 Internal Eye Opening Monitor (EOM)
- 8.3.8 Output Function Control
- 8.3.9 Output Driver Control
- 8.3.10 Status Indicators and Interrupts
- 8.3.11 Additional Programmability
- 8.4 Device Functional Modes
- 8.5 Register Maps
- 9 Application and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12器件和文檔支持
- 13機械、封裝和可訂購信息
8.4.1.1 SMBus Read and Write Transaction
SMBus is a 2-wire serial interface through which various system component chips can communicate with the master. Slave devices are identified by having a unique device address. The 2-wire serial interface consists of SCL and SDA signals. SCL is a clock output from the master to all of the slave devices on the bus. SDA is a bidirectional data signal between the master and slave devices. The LMH0397 SMBus SCL and SDA signals are open-drain and require external pullup resistors.
Start and Stop:
The master generates Start and Stop patterns at the beginning and end of each transaction, as shown in Figure 12.
- Start: High-to-low transition (falling edge) of SDA while SCL is high.
- Start: High-to-low transition (falling edge) of SDA while SCL is high.
Figure 12. Start and Stop Conditions The master generates nine clock pulses for each byte transfer as shown in Figure 13. The 9th clock pulse constitutes the ACK cycle. The transmitter releases SDA to allow the receiver to send the ACK signal. An ACK is recorded when the device pulls SDA low, while a NACK is recorded if the line remains high.
Figure 13. Acknowledge (ACK)