I have ordered some NXP UARTs one of which is the SC16IS750. It has an I2C/SPI interface and has a register set compatible with the venerable 16C450 as well as a 64 character transmit and receive FIFO. I have searched this forum and done a thorough Google search and haven't found any reference to this device in the context of Arduino.
Is anyone here aware of an Arduino library or example for this part? Since the original was a parallel interface device and the processors have a hardware UART built-in there probably hasn't been much interest. I wanted to double check before I duplicated anyone else's efforts.
There are significant advantages to using these devices in an application that does extensive serial i/o. The 64 character FIFO buffers reduce the use of Arduino RAM, they have their own baud rate generators so they free up a timer and they have an interrupt pin so they don't have to be polled during use. There are four software handshake character registers that make packet handling easier and they have automatic RS485 slave address detection. The 8-bit GPIO port has the full complement of hardware handshake lines defined or can be used as a general purpose i/o port.
They make a dual version as well but I'm going to hook up the single first.