Use the Smart Manual for the CS+ for CC integrated development environment.
You can quickly view the description of SFR (Special Function Register) or IOR (I/O Register) in the following panels by simply moving the mouse cursor over the register. (RL78 and RX only)
This function is available in CS+ for CC V6.00.00 and later.
See here for details about the Smart Manual.
|CS+ (formerly CubeSuite+)|