code: function xCMP( value ) {
  		var readValue = read(),
  			t = ( value - readValue ) & 0xff;
  		flagN = ( t & 0x80 ) && 1;
  		flagC = +( value >= readValue );
  		flagZ = +( t === 0 );
  	}
docs: Compare value with memory as if subtraction was carried out.
  @param {number} value - The value to compare with memory.