The chip we have chosen is apparantly attractive to a lot of other people as well. Essentially the same chip is offered by a number of different manufacturers. In an attempt to disguise this fact, the part numbers bear no noticable relationship, but a perusal of the data sheets makes this fact clear.
Our radio boards have been assembled using the Silicon Labs chip, so theirs is the definitive data sheet. However, the Microchip data sheet is more extensive and a bit better organized.Like the DAC and DDS chips in previous exercise, this chip is programmable. Unlike those chips, which were controlled by a single command word, our radio chip contains a number of different registers and can be read from as well as written to. To support the required level of performance over a serial connection, it uses the Serial Peripheral Interface or SPI protocol. Unlike I2C, this is not an official standard, so no definitive specification is available. However, an introduction and links to additional information may be found in the Wikipedia article on SPI.