ST16C552CJEC2.97 to 5.5 volt operation 
• 24MHz clock operation at 5V 
• 16MHz clock operation at 3.3V 
• 16 byte transmit FIFO 
• 16 byte receive FIFO with error flags 
• Full duplex operation 
• Transmit and receive control 
• Four selectable receive FIFO interrupt trigger levels 
• Standard modem interface 
• Compatible with ST16C450