There are already three different PIC32 families stacking on each other. Each new family introduced major changes in the SPI modules. The first family relied on unbuffered SPI similar to old 8-bit microcontrollers, the second family introduced buffering, while the third family introduced I2S compatibility (aka Audio Mode).
November 2007 Microchip introduced the PIC32 MX3-4 families of 32-bit microcontrollers. They were designed to be pin to pin compatible and share the same peripherals set with the PIC24FxxGA0xx family of devices allowing the use of common libraries, software and hardware tools.
July 2009 Microchip introduced the PIC32 MX4-5-6 families that provide up to 128 kbytes of RAM and extensive connectivity options, including 10/100 Mbps Ethernet, two CAN2.0b controllers, USB Host, Device and OTG, and 6 UART, 5 I2C and 4 SPI ports.
December 2011 Microchip introduced the PIC32 MX1-2 families featuring two I2S interfaces for audio processing. Does it mean all previous families were unable to deal with audio?
