HT46801B-1 Datasheet, Holtek Semiconductor

CPU Features
* Operating voltage:
* 6-level subroutine nesting
* All instructions executed in one or two instruction fSYS= 4MHz: 2.2V~5.5V fSYS= 8MHz: 3.3V~5.

The usual Holtek microcontroller features of low power consumption, I/O flexibility, timer functions, oscillator option.