The ADuC814 is a fully integrated 247 kSPS， 12-bit data acquisition system incorporating a high performance multichannel ADC， an 8-bit MCU， and program/data Flash/EE memory on a single chip. This low power device operates from a 32 kHz crystal with an on-chip PLL generating a high frequency clock of 16.78 MHz. This clock is， in turn， routed through a programmable clock divider from which the MCU core clock operating frequency is generated. The microcontroller core is an 8052 and is compatible with an 8051 instruction. 8 kBytes of nonvolatile Flash/EE program memory are provided on-chip. 640 bytes of nonvolatile Flash/EE data memory and 256 bytes RAM are also integrated on-chip. The ADuC814 also incorporates additional analog functionality with dual 12-bit DACs， a power supply monitor， and a band gap reference. On-chip digital peripherals include a watchdog timer， time interval counter， three timer/counters， and two serial I/O ports （SPI and UART）。 On-chip factory firmware supports in-circuit serial download and debug modes （via UART）， as well as single-pin emulation mode via the DLOAD pin. The ADuC814 is supported by a QuickStart? Development System. The part operates from a single 3 V or 5 V supply over the extended temperature range ?40°C to +125°C. When operating from 3 V supplies， the power dissipation for the part is below 10 mW. The ADuC814 is housed in a 28-lead TSSOP package.