General Description
The HT46R24/HT46C24 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 HT46C24 is fully pin and functionally compatible with the OTP version HT46R24 device.

FEATUREs
• Operating voltage:
    fSYS=4MHz: 2.2V~5.5V
    fSYS=8MHz: 3.3V~5.5V
• 40 bidirectional I/O lines (max.)
• 1 interrupt input shared with an I/O line
• Two 16-bit programmable timer/event counter with overflow interrupt
• On-chip crystal and RC oscillator
• Watchdog Timer
• 819216 program memory
• 3848 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
• 16-level subroutine nesting
• 8 channels 10-bit resolution A/D converter
• 4-channel 8-bit PWM output shared with four I/O lines
• Bit manipulation instruction
• 16-bit table read instruction
• 63 powerful instructions
• All instructions in one or two machine cycles
• Low voltage reset function
• I2C Bus (slave mode)
• 28-pin SKDIP/SOP, 48-pin SSOP package