TK87C751 Microcontroller, 64K Flash - 8 Bit Microcontroller with 8051 architecture - 64Kx8 Internal Flash ROM (2Kx8 in original) - 128 bytes of Internal RAM (64 bytes in original) - Low standby current at full supply voltage - 0-20 MHz operation Classic architecture instruction timing - 3 Bidirectional ports (19 bits) - 28 pin PLCC package Built in power management - Two Wire Interface (TWI) (I2CTM compatible) - 16 bit Timer/Counter with auto-reload. Fixed rate Timer - LED compatible outputs Direct replacement for Philips S83C751 / S87C751 microprocessors. - Implemented with the Tekmos Customer Configured Microprocessor (CCM) technology