CZ : Clear destination register (or set it to Imm16) if source register is Zero

If the source register (SRC1) is cleared (all bits are zero), then either ;

Short version : the destination register (SRC2) is cleared

Long version : the destination register (SRC2) is set to the value of Imm16 (sign-extended).

This is one of the conditional instructions of the CMOV group, see also : CLR, CNZ, CO/CNE/CNO/CE, CS/CNS