The register that stores the bits required to mask the interrupts is ______.

Answer: Interrupt mask register

Explanation: The interrupt mask register holds one bit for each interrupt source; each bit controls whether that interrupt can be delivered to the processor. Setting a mask bit usually disables (masks) the corresponding interrupt, while clearing the bit enables it.

• Interrupt mask register: Stores enable/disable bits for each interrupt source so specific interrupts can be masked.

• Interrupt request register: Records pending interrupt requests from devices but does not control masking.

• Status register: Contains processor condition flags and state bits, not the per-interrupt mask bits.

• Interrupt service register (term clarification): There is no common hardware register by this exact name; 'interrupt service routine' refers to the software handler for an interrupt, not a hardware mask register.