SLDU019B December   2015  – March 2016 PGA450-Q1

 

  1.   PGA450Q1EVM-S User's Guide and TIDA-00151 UART Demo Instructional
    1.     Trademarks
    2. 1 Introduction
    3. 2 Setup and Operation
      1. 2.1 Input and Output Connectors
      2. 2.2 Basic Operation
        1. 2.2.1 Programming the PGA450-Q1 DEVRAM or OTP Memory
        2. 2.2.2 Programming the PGA450-Q1 EEPROM
        3. 2.2.3 Testing the UART Connection With the TI GER Board
      3. 2.3 UART Command Listing
    4. 3 Software
      1. 3.1 IDE Output File Configuration
        1. 3.1.1 Setup for DEVRAM Output File
        2. 3.1.2 Setup for OTP Output File
      2. 3.2 Interface Descriptions
        1. 3.2.1 UART Interface
        2. 3.2.2 LIN Interface
        3. 3.2.3 Serial-Peripheral Interface
    5. 4 Schematic, Bill of Materials, and Layout
      1. 4.1 Schematic
      2. 4.2 Bill of Materials
        1. 4.2.1 BOM
      3. 4.3 Board Layout and Component Placement
    6. 5 References
  2.   Revision History

3.2.3 Serial-Peripheral Interface

The PGA450-Q1 device can also be put into a RESET state where the microcontroller is not active. During this state, SPI is the only digital interface that can be used. The low-side drivers can still be triggered to begin an ultrasonic burst and the analog front-end and digital data path can still store the returned echo signal in the FIFO RAM. However, any processing of the FIFO RAM by the internal microprocessor to determine the location of an object does not occur. The FIFO RAM data can be read over SPI, allowing an external microprocessor to process the data.

To provide a quick evaluation of the performance of the PGA450-Q1 device using the PGA450Q1EVM-S and GUI without having to develop sophisticated 8051 μP software, the GUI provides an intuitive interface tab, the Evaluation Tab, that collects all required information regarding the transducer drive and receive. For the transducer drive, it includes: transducer frequency; transducer drive voltage, VREG; transformer configuration; and number of drive pulses. For the transducer signal receive, it includes signal-processing parameters: LNA gain setting; BPF and LPF coefficient; clock selection; FIFO mode; and FIFO downsample size.