The S3C921F can be used for dedicated control functions in a variety of applications, and is especially designed for application with voice synthesizer or etc. The S3C921F/P921F single-chip 8-bit microcontroller is fabricated using an advanced CMOS process. It is built around the powerful SAM88RCRI CPU core. Stop and Idle power-down modes were implemented to reduce power consumption. To increase on-chip register space, the size of the internal register file was logically expanded. The S3C921F/P921F has 64 Kbytes of program ROM and 192 Kbytes of data ROM on-chip (S3C921F), and 720 bytes of RAM including 16 bytes of working register and 128 bytes of LCD display RAM. Using the SAM88RCRI design approach, the following peripherals were integrated with the SAM88RCRI core: -- Four configurable I/O ports including ports shared with segment/common drive outputs -- 8-bit programmable pins for external interrupts -- One 8-bit basic timer for oscillation stabilization and watch-dog functions -- One 8-bit and one 16-bit timer/counter with selectable operating modes -- Watch timer for real time