The HT66F20 with 1KB 64Byte FLASH RISC NSOP-16 Microcontroller Unit (MCU/MPU/SOC) ROHS is a single-chip, 8-bit microcontroller with a low power consumption and low voltage operation option. It is manufactured by Holtek and based upon their proprietary 8051 architecture core. The chip supports up to 8MHz clock frequency, has on-chip full speed USB support, in-system programability via UART or parallel port, and supports 8-channel 10-bit A/D, 4-Channel PWM and GPIO. It incorporates 1KB FLASH memory, 64-Bytes RAM, and 12 programmable I/O lines. It is also RoHS compliant, making it particularly suitable for use in all products designed with the European Union RoHS Directive in mind.