burst duration and the resulting intensity of radiation emitted from irda module 2 is approximately 40 mw sr at 875 nm when a remote control rc transmission is to occur however a digital rc control signal tx is generated by software executing on the cpu 4 using the codeset information 6 for additional detail on codesets on how codesets can be stored and on an exemplary way to generate an rc transmission from codeset information see u s patent application ser no 10 777 023 filed feb 10 2004 now u s pat no 7 259 696 and u s pat no 7 339 513 filed aug 27 2004 the entire subject matter of these two documents is incorporated herein by reference no microcontroller that stores codeset information need be provided where the irda circuit 1 is part of a personal digital assistant pda rather codeset information 6 is stored in main memory on the pda such that software executing on the cpu 4 of the pda can access the codeset information and use it to drive the irda rc tx terminal 19 with the rc tx signal this rc tx signal is provided to irda module 2 via the same irda rc tx terminal 19 that is used to supply the irda.