New STM8 8-bit Microcontroller from STMicroelectronics is ST7

STMicroelectronics has introduced an upgrade to their ST7 8-bit microcontroller architecture. Called the STM8, the new architecture is targeted towards low power 8-bit communications.

The STM8 microcontroller platform targets a wide range of applications including Automotive, Industrial, Consumer, and battery powered applications. The STM8 microcontroller technology allows engineers to design for either fast program execution, or low power.

The STM8 will be manufactured using ST's proprietary low power 130nm embedded non-volatile memory process technology. ST's 130nm process is a high integration mixed signal process that supports analog, digital, and true EEPROM over a wide voltage range. I/O pads have excellent ESD characteristics similar to the robust I/O pins on the ST6 8-bit microcontroller, and can withstand high injection currents without inducing crosstalk on adjacent pins.

The STM8 is an upgrade to ST's popular ST7 microcontroller, with architecture enhancements and a more powerful instruction set. The average performance of the STM8 is around 6x the average MIPS performance of the ST7. The peak performance of the STM8 is 10x the average performance of the ST7.

The STM8 is designed to meet Automotive Q100 Quality requirements and operate at temperatures of up to 145?C.

STM8 Family Features include:

• 24MHz Harvard architecture CPU
• Wide operating voltage range from 1.65V to 5V ¹
• 5V: Run current 1mA + (0.6mA x MHz) (typical) ¹
• 3V: Run current 1mA + (0.4mA x MHz) (typical) ¹
• Wait Current 1.6mA - CPU not clocked, all peripherals running ¹
• Halt Mode current 10µA typical, 25µA max ¹
• Average 1.8 cycles/instruction
• 8-bit ALU
• 3-stage CPU pipeline
• Single cycle fetch for most instructions
• Flash Memory with write protect
• Read Out Protection - blocks reading out memory contents, erases Flash and RAM if override is attempted
• True Data EEPROM
• 32-bit Program Memory Bus
• 24-bit Program Counter
• Up to 256KBytes of on-chip Flash Program Memory
• 16-bit stack pointer with relative addressing
• 16-bit X and Y index registers for indirect addressing
• 20 addressing modes
• 32 Interrupt Vectors, 3 priority levels.
• Internal 16MHz RC oscillator
• Internal 128KHz oscillator
• Low Power modes
• 8x8 multiplication
• 16/8 and 16/16 divide
• Single Wire debug

¹ Initial product specifications

All specifications are per STMicroelectronics STM8AF5166 example datasheet at 5V supply current unless otherwise specified.

STM8 Microcontroller

The STM8 uses many of the same modular peripherals as ST's 32-bit product line. STM8 available peripherals include:

• Clock Security System (CSS) protects against clock failure
• Dual Watchdog timers each with independent clock sources
• 16-bit CAPCOM timers with up to 4 CAPCOM channels per timer
  - a CAPCOM channel can be IC, OC, or PWM
• 16-bit PWM timers with 3 complimentary outputs and adjustable dead time for inverter control and BLDC
• 10-bit (±3-bits) SAR A/C with 7µsec conversion time
• 8-bit System Timer
  - Single or continuous conversion
  - Analog watchdog function
  - Scan mode
• USART supports SPI, LIN (master)
• LIN-UART (LIN master/slave) with automatic synchronization
• SPI @ up to 10 Mbits/sec
• I2C @ 400Kbits/sec
• IrDA
• SMBUS
• PMBUS
• Bootloader for in-circuit Flash programming through UART, LIN, and CAN
• CAN (2.0A.B) @ 1 Mbits/sec

STM8 Development Tools
The STM8 is supported by a full range of development tools, including the sophisticated STice In-Circuit Emulator, which has a USB 2.0 PC interface and 8-bit probe analyzer. The STM8 is also supported by the STVD C Compiler and debugger toolset, and a range of starter kits and evaluation boards.

Cosmic C provides a C Compiler for the STM8 (a free 16Kbyte limited version is available). In addition, Raisonance provides the R-Link low-cost single-wire debug interface and will soon offer a C Compiler.

About STMicroelectronics
STMicroelectronics is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2007, the Company's net revenues were $10 billion.