it wasnt my answer !!!!!!!!!!!!!!!!!!!!!!!!!
im working by 8051 ,is it old or not ,im working ans i wanna know the defects of working with high frequency?
Workingwith 8051 in higher frequiencies causes problems of stray crystal oscillations and controller may not work or behave properly. For working at high frequencies, go for MILITARY / INDUSTRIAL grade of 8051 controllers, and definetely 8051 are old. These are in the market since a decade or more.
Hi,
It is true that 8051 architecture is old, but you get many new devices with this architecture for working at high frequencies, for more info. please visit Silicon Labs, Atmel, or Philips (NXP Semiconductors) sites.