Specifications:

Core Processor: 8051
Core Size: 8-Bit
Speed: 24MHz
Connectivity: UART/USART
Peripherals: Brown-out Detect/Reset, LED, POR
Number of I/O: 15
Program Memory Size: 4KB (4K x 8)
Program Memory Type: FLASH
EEPROM Size: N/A (Not specified)
RAM Size: 128 x 8
Voltage - Supply (Vcc/Vdd): 4V ~ 6V
Data Converters: N/A (Not specified)
Oscillator Type: Internal
Operating Temperature: -40°C ~ 85°C (TA)
Mounting Type: Through Hole
Package / Case: 20-DIP (0.300", 7.62mm)
Supplier Device Package: 20-PDIP
Base Product Number: AT89C4051