dear sir/madam(s), I define simple structure in c(keil)for at89c52 mcu as bellow. struct MODE { YEAR:5; MONTH:5 }; struct MODE RUN,NON_RUN_MODE; My question is will my veriable RUN.YEAR ,NON_RUN_MODE.YEAR,RUN.MONTH,RUN.MONTH will assigned in bit data memory best regards satish munot