Path: OKDatasheet > Semiconductor Datasheet > Atmel Datasheet > T89C51RD2-SLUC-L
T89C51RD2-SLUC-L manual: "0 to 25 MHz flash programmable 8-bit microcontroller, 80C52 compatible, 8051 pin and instruction compatible, 256 bytes RAM, EEPROM 2Kbytes, flash 64Kbytes"