Texas Instruments TUSS44 0 Series, Руководство пользователя

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20 SLAU822A – December 2019 – Revised April 2020
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TUSS44x0 EVM for Ultrasonic Sensors User's Guide
3.5.3 Interface Mode
The TUSS44x0 devices offers a SPI modes of communication to interface with a master controller. The
SPI interface offers complete register access, and compatibility of the 3.3-V and 5.0-V low-logic level
serial communication format for direct interfacing to other micro-controllers.
3.5.3.1 Serial Peripheral Interface (SPI)
The TUSS44x0 device includes a SPI digital communication interface. The main function of the SPI is to
enable writes to and reads from all addresses available for SPI access, including access to all user RAM
register memory locations on the TUSS44x0 device. The SPI digital communication is a master-slave
communication link in which the TUSS44x0 is a slave device only. The master device controls when data
transmission begins and ends. The slave device does not transmit data back to the master until it is
commanded to do so by the master.
Figure 17. Interface - SPI
The SPI page contains elements to configure master's SPI port, and manually send and receive command
data. The controls available on the
SPI tab are as follows:
• Setup
Clock Rate — As part of the SPI configuration, the user can specify a SPI clock of up to 8 MHz. The
GUI's default clock rate is 1 MHz.
Configure Button — Applies the SPI configuration settings to the micro-controller.
• Single Frame Communication
Read/Write Button — S ends a 16-bit SPI read/write frame.
Single R/W Scripting Input — Allows for multiple 16-bit SPI read/write frames based on the following
hex-input format with a semicolon delimiter: PACKET0;PACKET1;PACKET2 . For example:
2A8C;01FF;50B4;...
Run Script — Runs the loaded script input. Each read/write command is executed with a 500 ms
delay.
• IO Pin Configuration
OUT HI — Immediately sets the state of the IOx pin to a logic-high 3.3-V output.
OUT LO — Immediately sets the state of the IOx pin to a logic-low 0-V output.
IN HI-Z — Immediately sets the state of the IOx pin to a floating input.
3.5.4 Memory Map
The memory map is used to read and write to all of the device registers. The memory map columns from
left-to-right display the hex address and register name, the current 8-bit hex value of the register, and
individual bit values.