An interrupt that can be turned off by the programmer is known as Maskable interrupt.

Execution Unit receives program instruction codes and data from BIU, executes these instructions and store the result in general registers.

In 8086 Carry flag, Parity flag, Ausiliary caarry flag, Zero flag, Overflow flag, Trace flag, Interrupt flag, Direction flag, and Sign flag.

Use the concept of register-retiming.

divide the totla combinatorial delay in two segments such that individually the delay is less the clock period.

this can be done by inserting a flip-flop in the combinational path.

e.g.,

clock period --- 5 ns

total cominational delay ---- 7

then divide the 7ns path in two path of 4 or 3 (best resutls are obtained if delays are  same for both path i.e 3.5ns) by inserting a flip-flop in between.