This page provides a comparison of the groups in the 32-pin offering. Starting with operating voltage, there is only one exception to 2.2V operation within the 2x series, the R8C/2E-2F. Since these devices are part of the ASSP (application specific standard product) targeted lighting applications, they were designed to operate only down to 2.7V. These groups also provide a wide range of memory (ROM or RAM) options to meet different needs. In terms of serial communication, there are different levels of peripherals ranging from a single serial channel in the R8C/2E-2F, up to six different options combining asynchronous, synchronous, SPI and I²C in the R8C/33x devices.