# How does Atmel's XMEGA numbering scheme work?

Atmel has several series of XMEGA chips. How does the numbering scheme work?

• I don't see a problem with questions of the format "What's the difference between these two similar part numbers?" – endolith Aug 8 '11 at 16:47
• I have had many times that I have seen odd numbering schemes that are not overly obvious as to what they mean. Asking this type of question can very much help with the electronic design process. – Kellenjb Aug 8 '11 at 18:54

ATxmega128A1U

From the current parts list, I gather the first number nnn is the amount of flash in kilobytes. The letter L is one of A or D, the cheaper D parts have no DMA or DAC. The number m is 1, 3, 4 for 100, 64, 44 pin parts, and a U suffix signifies a part with USB.