Hitachi HMCS46C (HD44840), HMCS46CL (HD44848)
The HMCS46C is a CMOS 4-bit microcontroller which contains ROM, RAM, I/O and Timer/Counter on a single-chip. The HMCS46C is designed to perform controller function as well as arithmetic function for both binary and BCD data. Its CMOS technology provides the flexibility of microcomputers for battery powered an battery back-up applications.
The HMCS46C contains its own oscillator and frequency divider (CPG). The user can obtain the desired timing for operation by merely connecting a resistor Rf or ceramic filter circuit (Internal Clock Operation). Also an external oscillator can supply a clock (External Clock Operation). The maximum Clock Oscillation Frequency is 900 KHz for HMCS46C and 250 KHz for HMCS46CL.