1. A method of executing a machine instruction in a central processing unit, the method comprising: obtaining, by a processor, a machine instruction for execution, the machine instruction being defined for computer execution according to a computer architecture, the machine instruction comprising: at least one opcode field to provide an opcode, the opcode identifying a convert to zoned from decimal floating point function; a first register field designating a first register, the first register comprising a first operand; a second register field and a displacement field, wherein contents of a second register designated by the second register field are combined with contents of the displacement field to form an address of a second operand; and a mask field, the mask field comprising one or more controls used during execution of the machine instruction, the mask field comprising a zone control to control a zone field of the second operand; and executing the machine instruction, the executing comprising: converting at least a portion of the first operand in a decimal floating point format to a zoned format, wherein the converting comprises: converting a first plurality of bits of first operand to corresponding triplets of zoned digits, the triplets of zoned digits being provided as a first portion of a result; converting a second plurality of bits of the first operand to a most significant zoned digit of result; and providing the zone field for each zoned digit of the result; and placing the result at a location designated by the address of the second operand, wherein the result is stored to the location in the zoned format absent issuing one or more additional machine instructions to convert the stored result to the zoned format.