General Description
The HT46R22/HT46C22 are 8-bit, high performance, RISC architecture microcontroller devices specifically designed for A/D applications that interface directly to analog signals, such as those from sensors. The mask version HT46C22 is fully pin and functionally compatible with the OTP version HT46R22 device.

FEATUREs
Operating voltage:
   f_SYS=4MHz: 2.2V~5.5V
   f_SYS=8MHz: 3.3V~5.5V
19 bidirectional I/O lines (max.)
1 interrupt input shared with an I/O line
8-bit programmable timer/event counter with overflow interrupt and 7-stage prescaler
On-chip crystal and RC oscillator
Watchdog Timer
204814 program memory
648 data memory RAM
Supports PFD for sound generation
HALT function and wake-up feature reduce power consumption
Up to 0.5s instruction cycle with 8MHz system clock at VDD=5V
6-level subroutine nesting
8 channels 9-bit resolution (8-bit accuracy) A/D converter
1-channel (6+2)/(7+1)-bit PWM output shared with one I/O line
Bit manipulation instruction
14-bit table read instruction
63 powerful instructions
All instructions in one or two machine cycles
Low voltage reset function
I2C Bus (slave mode)
24-pin SKDIP/SOP package