IC Selection

We have done some reseacrh regarding IC selection on which one should we choose between AT89C52 or AT89S52. During our simulation we used AT89C52 and 8052. We have observed the power consumption and connection port between these IC and other configuration. 

AT89S52

The 89S52 has 4 different ports, each one having 8 Input/output lines providing a total of 32 I/O lines. Those ports can be used to output DATA and orders do other devices, or to read the state of a sensor, or a switch. Most of the ports of the 89S52 have 'dual function' meaning that they can be used for two different functions.

The first one is to perform input/output operations and the second one is used to implement special features of the micro controller like counting external pulses, interrupting the execution of the program according to external events, performing serial data transfer or connecting the chip to a computer to update the software. Each port has 8 pins, and will be treated from the software point of view as an 8-bit variable called 'register', each bit being connected to a different Input/Output pin.

AT89C52

AT89C52 is an 8-bit microcontroller and belongs to Atmel's 8051 family. AT89C52 has 8KB of Flash programmable and erasable read only memory (PEROM) and 256 bytes of RAM. AT89C52 has an endurance of 1000 Write/Erase cycles which means that it can be erased and programmed to a maximum of 1000 times. Though very slight difference between the features of AT89C51 and AT89C52, they are very similar in their pin configurations* and operations.The pin configuration of AT89C52 is exactly similar to that of AT89C51 except that the first two pins, P1.0 and P1.1 are multiplexed to correspond to Timer2 operations. 

While AT89C51 has two timers (Timer0 & Timer1), AT89C52 also has Timer2. Corresponding to Timer2, there are extra SFRs (Special Function Registers) T2CON & T2MOD. Also there are registers RCAP2H & RCAP2L to configure 16 bit Capture & Auto-reload modes of Timer2.

Difference between AT89C52 and AT89S52:

The 8051 structure of AT89c52 and AT89s52 are the same,but the type of flash is different,for AT89c52 the VPP range is between 5V-12V while for AT89s52 only 12v can be selected. For the purposes of Proteus simulation, the AT89S62 and the AT89C52 are the same. Presumably we  simulating run-time functionality, rather than electrical behavior at programming time. In any case, Proteus cannot simulate the actual in-circuit programming of its micro controller models. AT89s52 is "In-System" programable whereas AT89c52 is programmed with the programmer. AT89S52 has several new registers (AUXR, AUXR1, WDTRST, DP1L, DP1H) in comparison with AT89C52. Also there are a lot of variables in RAM. the AUXR register by default in the AT89S52 series are reset to 0x00,so the ALE always emits 1/6 the oscillator frequency