SCEA065B November   2018  – March 2021 SN74AVC4T774 , SN74AXC1T45 , SN74AXC4T245 , SN74AXC4T774 , SN74AXC8T245 , SN74AXC8T245-Q1 , SN74AXCH1T45 , SN74AXCH4T245 , SN74AXCH8T245

 

  1.   Trademarks
  2. 1Introduction
  3. 2Common Interfaces and AXC Implementation
    1. 2.1 General Purpose Input Output (GPIO)
    2. 2.2 Serial Peripheral Interface (SPI)
      1. 2.2.1 Voltage Translation for SPI
      2. 2.2.2 SPI Applications
    3.     8
    4. 2.3 UART
      1. 2.3.1 Voltage Translation With UART
      2. 2.3.2 UART Applications
    5. 2.4 Joint Test Action Group (JTAG)
      1. 2.4.1 JTAG Applications
    6. 2.5 Reduced Gigabit Media Independent Interface (RGMII)
      1. 2.5.1 Voltage Translation for RGMII
      2. 2.5.2 RGMII Applications
      3. 2.5.3 Skew Performance
  4. 3Summary
  5. 4Related Documentation
  6. 5Revision History

2.1 General Purpose Input Output (GPIO)

All microprocessors have General purpose input output (GPIO) ports for communication with the peripheral devices. However, the core and peripheral chips might work at different voltage levels, which is why the system would need a level shifter. If the required signals are not shifted to the voltage at which the microprocessor is operating, it impacts the reliability of communication. The SN74AXC1T45 can be implemented as part of the I/O circuit, especially in single channel signals such as control inputs. The SN74AXC1T45 provides a solution for voltage translating I/O pins such as the following:

  • Enable
  • Restart
  • Clock buffering
  • Power good
  • Error flag
  • Reset
  • Memory error
  • Processor overheat
  • LED driving as shown in Figure 2-1
GUID-A5C22ABE-E04D-410E-B087-B22FA24C022A-low.gifFigure 2-1 GPIO Translation Using SN74AXC1T45 for LED Driving