HLT

Instruction Name	Halt
Mnemonic	HLT
CP1610 Clock Cycles	Infinity
Interruptible	No
Opcode Range	$0000
Input Flags	None
Output Flags	None
Addressing Mode	Implied

The Halt (HLT) instruction halts the CP1610. The CPU performs no further processing after receiving this instruction. This also means that all further masked interrupts are ignored as well until the CPU gets reset.

Currently, it is unknown whether an unmasked interrupt arriving on the INTR input, or if a pulse on the STPST input will restart a halted CPU. The existing CP1610 documentation does not say. On the Intellivision, this is irrelevant as both inputs are tied to fixed values. HLT is mainly useful for debugging.