AT89C52 Microcontroller

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 differences between AT89C51 and AT89C52 have been tabulated below.

	AT89C52	AT89C51
RAM	256 Bytes	128 Bytes
Flash	8 KB	4 KB
Number of Timers/Counters	3 (16-bit each)	2 (16-bit each)
Number of Interrupt Sources	8	6

*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 as given in the following table.

Existing	Alternate	Function
P1.0	T2	Timer/counter 2 External Count input
P1.1	T2 EX	Timer/counter 2 Trigger input

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.