ChordBits lets you quickly build registers containing groups of bits within them, which reflect the register structure as depicted in the data sheet. Register Editor, to obtain a register view. You can then use that register view to turn bits on and off and view the calculated value in four bases: Decimal, hex, octal, and binary.
It works also the other way around. You can set a decimal value and have it reflected into the register view.
There is also a raw bits window, where you can view a set of 32 bits regardless of any register. It is possible to toggle between the register view and the raw bits view.
ChordBit lets you work with several registers at the same time, each register in its own window. ChordBits will remember the state of all your open windows, and restore them on the next activation. This way you work with the set of registers related to your current task without having to reload them all every time. It's also possible to save the windows' state to a special session file.