The devices contain 16K ~ 64K bytes of Flash Program Memory, 4K ~ 8K bytes of SRAM Data Memory together with an integrated hardware divider for higher operational performance. These devices also provide abundant peripheral resources including a 12-channel 1 Msps SAR A/D Converter, 16-channel 16-bit PWM, as well as a wide range of other high speed peripherals such as USART interface, UART interface, SPI interface, I2C interface, real time clock, etc.

Additional functions include high precision internal RC oscillators that provide both 20 MHz and 32 kHz frequency clock sources. An internal clock monitor function is used to automatically switch to the internal oscillator when an ineffective external crystal oscillator situation arises. The full device range include multiple power saving management modes, power-on reset, multi-level low voltage detection (LVD), brownout detection (BOD) etc., which combine to ensure a safe and stable system operating environment.

The devices are supplied in 28-pin SOP, 24/28-pin SSOP, 24/33-pin QFN and 44/48-pin LQFP package types and contain from 18 to 40 GPIO pins. For the 28-pin SOP and 44/48-pin LQFP packages, an independent power supply pin, VDDIO, is supplied and can be used to provide an additional I/O operating voltage of 1.8 V ~ 5.5 V, ensuring better resources and product usage flexibility.

With regard to development tools, the devices are fully supported by professional IDE suppliers including IAR and Keil. Additionally, Holtek also provides its own low cost demo boards and development platform kits. The Holtek development platform includes an ICE e-Link32 Pro, a full set of peripheral driver program libraries, a range of application example source code as well as application development handbooks. With Holtek's integrated ISP (In System Programming) and IAP (In Application Programming) technology, all the tools are at hand for rapid firmware updates and improvements to product flexibility and production efficiency, features which combine to allow customers to reduce their development time and seize initiatives for new product market entry.