there are couple of them.....refer the following or go on atmel's site too...
Device Flash (Kbytes) ISP Self Program Memory EEPROM (Bytes) SRAM (Kbytes) Max. Operating Frequency CPU Operating Voltage (Vcc) Max I/O Pins UART Timers Watchdog SPI TWI (I2C) ADC Channels ADC Resolution (bits) ADC Speed (ksps) Packages Green Packages
AT89S51 4 SPI -- -- 0.125 24 8051-12C 4.0 to 5.5 32 1 2 Yes -- -- -- -- -- *TQFP 44*PDIP 40*PLCC 44
AT89S52 8 SPI -- -- 0.25 24 8051-12C 4.0 to 5.5 32 1 3 Yes -- -- -- -- -- *TQFP 44*PDIP 40*PLCC 44
AT89LS51 4 SPI -- -- 0.125 16 8051-12C 2.7 to 4.0 32 1 2 Yes -- -- -- -- -- *TQFP 44*PDIP 40*PLCC 44
AT89LS52 8 SPI -- -- 0.25 16 8051-12C 2.7 to 4.0 32 1 3 Yes -- -- -- -- -- *TQFP 44*PDIP 40*PLCC 44
AT89C51AC2 32 UART API 2048 1.25 40 8051-12C 3.0 to 5.5 34 1 4 Yes -- -- 8 10 62.5 *PLCC 44*LQFP 44
AT89C51RB2 16 UART API -- 1.25 60 8051-12C 2.7 to 5.5 32 1 4 Yes 1 -- -- -- -- *PDIP 40*PLCC 44*LQFP 44
AT89C51RC2 32 UART API -- 1.25 60 8051-12C 2.7 to 5.5 32 1 4 Yes 1 -- -- -- -- *PDIP 40*PLCC 44*LQFP 44
AT89C5115 16 UART API 2048 0.5 40 8051-12C 3.0 to 5.5 20 1 4 Yes -- -- 8 10 62.5 *PLCC 28*SOIC 28*LQFP 32
AT89C51RD2 64 UART API -- 2 60 8051-12C 2.7 to 5.5 32 1 4 Yes 1 -- -- -- -- *PLCC 44*PLCC 68*LQFP 64*LQFP 44
AT89C51ED2 64 UART API 2048 2 60 8051-12C 2.7 to 5.5 32 1 4 Yes 1 -- -- -- -- *PLCC 44*PLCC 68*LQFP 64*LQFP 44
AT89C51ID2 64 UART API 2048 2 60 8051-12C 2.7 to 5.5 32 1 4 Yes 1 1 -- -- -- *PLCC 44*LQFP 44
AT89C51IC2 32 UART API -- 1.25 60 8051-12C 2.7 to 5.5 34 1 4 Yes 1 1 -- -- -- *PLCC 44*LQFP 44
AT89S8253 12 SPI -- 2048 0.25 24 8051-12C 2.7 to 5.5 32 1 3 Yes 1 -- -- -- -- *TQFP 44*PDIP 40*PDIP 42*PLCC 44
AT89C51AC3 64 UART API 2048 2.25 60 8051-12C 3.0 to 5.5 32 1 4 Yes 1 -- 8 10 62.5 *PLCC 44*LQFP 64*LQFP 44*PLCC 52
AT89S2051 2 SPI -- -- 0.25 24 8051-12C 2.7 to 5.5 15 1 2 -- -- -- -- -- -- *SOIC 20*PDIP 20
AT89S4051 4 SPI -- -- 0.25 24 8051-12C 2.7 to 5.5 15 1 2 -- -- -- -- -- -- *SOIC 20*PDIP 20
AT89C51RE2 128 UART/OCD API -- 8.25 60 8051-12C 2.7 to 5.5 34 2 4 Yes 1 -- -- -- -- *PLCC 44*LQFP 44
I tried uploading excel sheet but could not able to attach....
So copy peased it you can go to line
Atmel Products - 8051 Architecture - Flash ISP (In-System Programmable)
and download excel sheet....
Good Luck