HT56R22/HT56R23/HT56R24/HT56R25/HT56R26 -- TinyPowerTM A/D Type 8-Bit OTP MCU with DAC
General Description
These TinyPowerTM A/D Type 8-bit high performance RISC architecture microcontrollers are specifically, designed for applications that interface directly to analog signals. The devices include an integrated multi-channel Analog to Digital Converter, Pulse Width Modulation and and DAC outputs.
With their fully integrated SPI and I2C functions, designers are provided with a means of easy communication with external peripheral hardware. The benefits of integrated A/D, PWM and DAC functions, in addition to low power consumption, high performance, I/O flexibility and low-cost, provides the device with the versatility for a wide range of products in the home appliance and industrial application areas. Some of these products could include electronic metering, environmental monitoring, handheld instruments, electronically controlled tools, motor driving in addition to many others.
The unique Holtek TinyPower technology also gives the devices extremely low current consumption characteristics, an extremely important consideration in the present trend for low power battery powered applications. The usual Holtek MCU features such as power down and wake-up functions, oscillator options, programmable frequency divider, etc. combine to ensure user applications require a minimum of external components.

Features
CPU Features
Operating voltage:
fSYS=32768Hz: 2.2V~5.5V
fSYS=4MHz: 2.2V~5.5V
fSYS=8MHz: 3.0V~5.5V
fSYS=12MHz: 4.5V~5.5V
Up to 0.33us instruction cycle with 12MHz system clock at VDD=5V
Idle/Sleep mode and wake-up functions to reduce
power consumption
Oscillator types:
External 32768Hz Crystal -- LXT
External RC -- ERC
Internal 4/8/12MHz RC -- HIRC
External high frequency crystal -- HXT
Internal 32kHz RC -- LIRC
Four operational modes: Normal, Slow, Idle, Sleep
Fully integrated internal 4MHz, 8MHz and 12MHz oscillator requires no external components
All instructions executed in one or two instruction cycles
Table read instructions
63 powerful instructions
Up to 12-level subroutine nesting
Bit manipulation instruction

Peripheral Features
OTP Program Memory: 2Kx14 ~ 32Kx16
RAM Data Memory: 128x8 ~ 2304x8 Bits
Watchdog Timer function
Up to 50 bidirectional I/O lines
8 channel 12-bit ADC
Up to 4 channel 12-bit PWM
Software controlled 4-SCOM lines LCD driver with 1/2 bias
Multiple pin-shared external interrupts
Up to three 8-bit programmable Timer/Event Counter with overflow interrupt and prescaler
Up to one 16-bit programmable Timer/Event Counter with overflow interrupt
Serial Interfaces Module - SIM for SPI or I2C
Time-Base functions
Low voltage reset function
Low voltage detect function
PFD/Buzzer for audio frequency generation
12-bit Audio DAC output
Wide range of available package types