[51] 8051 programming and execution

[tapu]

Hi, I am using AT89c51.I am making project.problom is If I write program 1780 bytes then controller runs partially & lcd shows message but keypad does not work.if I write above 2080 bytes then controller takes too time to start running. and RTC time & date not displayed.I am using USB programmer & keil(unlicensed).

 

[kushal nandanwar]

check crystal frequency

 

[tapu]

crystel frequency is 11.0592 MHz

 

[jigarpatelp]

You have to provide your schematic and code only then any other can help you.

 

[ashad]

Check the voltage on ALE (pin30) voltages, if it is less then 1.6v then it may be because of ur Crystal ...