Features:

Product Name: AVR/AT89S51-24PU
SN: AT89S51-24PU
Product Number: SP-C9438
Footprint: PDIP-40P6
AT89S51-24PU
Flash (Kbytes): 4
Pin Count: 44
Max. Operating Freq. (MHz): 24
CPU: 8051-12C
Max I/O Pins: 32
UART: 1
SRAM (Kbytes): 0.125
Operating Voltage (Vcc): 4.0 to 5.5
Timers: 2
ISP: SPI
Watchdog: Yes
Packages: DIP-40

Dataheet: Download Datasheet