8259 Interrupt Controller OCW2 register

Hi all,

I am trying to figure out how an 8259 OCW2 register behaves, more 
specifically if the "Automatic Rotation" bits of OCW2 are latched or not.

For example, if I want to automatically rotate interrupt priorities on a 
Non-Specific EOI, do I

a) Issue a "Rotate on non-specific EOI command" to OCW2 during 
initialisation and then issue a Non-Specific EOI at the end of my ISR.

or

b) I issue a "Rotate on non-specific EOI command" at the end of my ISR.

Thanks
Hans.