How to Use SC16IS750: Examples, Pinouts, and Specs

The SC16IS750, manufactured by NXP Semiconductors, is a high-performance I2C/SPI to UART bridge. This versatile component enables seamless serial communication between microcontrollers and other devices. It features a built-in 64-byte FIFO buffer for both transmit and receive operations, supports a wide range of baud rates, and can be configured for either I2C or SPI communication protocols.

• Serial communication with microcontrollers in embedded systems
• Expanding UART interfaces in systems with limited UART ports
• Communication with sensors, modems, or other UART-based peripherals
• Industrial automation and IoT devices requiring reliable data transmission
• Debugging and monitoring serial data streams

The SC16IS750 is designed to provide robust and flexible serial communication. Below are its key technical details:

The SC16IS750 is available in multiple package types. Below is the pin configuration for the TSSOP28 package:

1. Power Supply: Connect the VDD pin to a 2.5 V to 3.3 V power source and the VSS pin to ground.
2. Communication Protocol Selection:
   • For I2C: Connect the SCL and SDA pins to the I2C bus of the microcontroller.
   • For SPI: Connect the SCLK, MOSI, and MISO pins to the SPI bus of the microcontroller.
3. UART Interface: Connect the TXD and RXD pins to the UART device for serial communication.
4. Address Configuration: Use the A0, A1, and A2 pins to set the I2C address or SPI chip select.
5. Interrupt Handling: Connect the IRQ pin to the microcontroller to handle interrupts.
6. Crystal Oscillator: Connect a crystal oscillator to the XTAL1 and XTAL2 pins for clock generation.

• Pull-Up Resistors: For I2C communication, ensure pull-up resistors are connected to the SCL and SDA lines.
• Baud Rate Configuration: Configure the baud rate registers to match the UART device's baud rate.
• FIFO Management: Use the FIFO buffer to handle high-speed data transmission efficiently.
• Reset: Use the RESET pin to initialize the device during power-up or after a fault condition.
• Voltage Levels: Ensure that the I/O voltage levels are compatible with the microcontroller.

Below is an example Arduino sketch to communicate with the SC16IS750 over I2C:

#include <Wire.h> // Include the Wire library for I2C communication

#define SC16IS750_ADDR 0x48 // Replace with the actual I2C address of the SC16IS750

void setup() {
  Wire.begin(); // Initialize I2C communication
  Serial.begin(9600); // Initialize serial communication for debugging

  // Configure SC16IS750 (example: set baud rate to 9600)
  Wire.beginTransmission(SC16IS750_ADDR);
  Wire.write(0x03); // LCR register address
  Wire.write(0x80); // Enable access to baud rate registers
  Wire.endTransmission();

  Wire.beginTransmission(SC16IS750_ADDR);
  Wire.write(0x00); // DLL register address
  Wire.write(0x60); // Set baud rate divisor (9600 baud)
  Wire.endTransmission();

  Wire.beginTransmission(SC16IS750_ADDR);
  Wire.write(0x01); // DLM register address
  Wire.write(0x00); // Set baud rate divisor (9600 baud)
  Wire.endTransmission();

  Wire.beginTransmission(SC16IS750_ADDR);
  Wire.write(0x03); // LCR register address
  Wire.write(0x03); // 8 data bits, no parity, 1 stop bit
  Wire.endTransmission();

  Serial.println("SC16IS750 configured successfully!");
}

void loop() {
  // Example: Send data to SC16IS750
  Wire.beginTransmission(SC16IS750_ADDR);
  Wire.write(0x00); // THR register address
  Wire.write("Hello, SC16IS750!"); // Send a string
  Wire.endTransmission();

  delay(1000); // Wait for 1 second
}

1. No Communication with the SC16IS750:

   • Verify the I2C or SPI connections and ensure proper pull-up resistors are used for I2C.
   • Check the I2C address or SPI chip select configuration.
   • Ensure the power supply voltage is within the specified range.

2. Data Loss or Corruption:

   • Ensure the baud rate is correctly configured on both the SC16IS750 and the UART device.
   • Use the FIFO buffer to handle high-speed data transmission.

3. Interrupts Not Triggering:

   • Verify the IRQ pin connection to the microcontroller.
   • Check the interrupt enable registers in the SC16IS750.

Q: Can the SC16IS750 operate in both I2C and SPI modes simultaneously?
A: No, the SC16IS750 can operate in either I2C or SPI mode, but not both simultaneously. The mode is determined by the hardware connections.

Q: What is the maximum UART baud rate supported?
A: The SC16IS750 supports UART baud rates up to 5 Mbps.

Q: How do I reset the SC16IS750?
A: Use the RESET pin to perform a hardware reset or write to the appropriate register for a software reset.

Q: Can I use the GPIO pins for custom functions?
A: Yes, the GPIO pins can be configured as general-purpose inputs or outputs.