Hello How can I get a simulation for stm ICs ?please help me .with thanks
Why do you want simulation?
Why not just get a cheap Nucleo board, and use a real chip?!
(the Nucleo boards have a built-in STLink - so you can do single stepping, examine memory, registers, etc)
ST makes dozens of parts, look through the inventory of parts supported by Keil to see which ones have the level of simulation you want. Or pick a generic ARM part.
Real boards are cheap, you are likely not paying Keil for tools, adjust your expectations accordingly. Learn how to program in C on a PC