optimal pwm using 89sxx

i'd like generate pwm output like diagram below, but until today i can't make it, first time i create usual pwm
later my owm output will be attached in h-bridge for control speed motor AC.i'm using microcontroller at89s51/52
anyone can help?[/url]

89Sxx doesn't have hardware PWM generator. Using software you can do it but the PWM frequency you will obtain at 8-bit resolution will be very less (around few hundred Hz). This will result in poor effeciency and jurky operation of motors.

Insted of 89Sxx use P89C51RD2/AT89C51RD2 (Philips or Atmel) which has 5 inbuilt hardware PWM generators. You can get high PWM frequencies around 16KHz using 11.0592MHz crystal which is quite sufficient for most control applications.

in my country at89c51/52 is it ok ?
so can you give me link to create pwm output like the picture i attached.
isn't at89s better than at89cxx ?
sorry i'm wrong

Yes ofcourse 89Sxx is better than 89Cxx . But 89C51RD2 is much much better than 89Sxx or 89Cxx. 89C51RD2 is not exactly same as 89C51. It has lot of extra peripherals and features. Check out its datasheet from Philips/Atmel website. As I said earlier the RD2 has in-built hardware PWM generator which will make your task simpler and reduce overhead on the CPU.