Atmel Optimizing AVR for Low-Power 32-bit MCU Markets

At the upcoming Embedded Systems Conference (April 2-4, 2007) Atmel will reveal details on the second generation of the 32-bit version of the AVR family, AVR32 UC3.

The AVR architecture was introduced by Atmel several years ago in the 8-bit MCU market. In recent years it has offered a 32-bit MCU version to aid its customers in a migration path, a strategy pursued by several MCU vendors.

Atmel’s latest development for AVR32 is optimized for low-power. One key feature is going to a three stage pipeline from the current seven stage. The single-cycle read/write SRAM is integrated into the core, thus it is in the pipeline. According to Atmel, with the SRAM having direct interface to the CPU that bypasses the system bus, the CPU is able to achieve faster execution.

Another key feature touted by Atmel to achieve low power and low cost is higher code density. This is achieved with an instruction set architecture (ISA) it shares with its AVR32 AP parent, but with over 220 instructions available as 16-bit compact and 32-bit extended instructions. The compiler automatically selects the most efficient compact or extended form of each instruction. Atmel also includes DSP functions.

The compact code also reduces the memory footprint required. The on-chip Flash is arranged in two banks to avoid wait state latency.

The main objective Atmel has for the AVR32 UC3 is to reduce the clock cycles. Fewer clock cycles leads to higher performance, but it also reduces power consumption.

There are versions with Ethernet Bus Interface (EBI) and others offered without EBI. In 10K unit prices range from $5.35 (128KB Flash, no EBI, QFP100) to $8.16 (512KB Flash, EBI, QFP144).

Semico Spin

Atmel has seen fast growth for its AVR architecture in both the 8-bit and 32-bit MCU markets. Semico sees the 32-bit MCU market as the fastest growing segment of the MCU market. Atmel is targeting the AVR32 for applications such as industrial control, building automation and security. Other markets are networked home and consumer along with control panels and monitoring. Other major 32-bit MCU vendors (NEC, Freescale, and Renesas) are more heavily focused on automotive.

Atmel claims improved code density, lower power and lower cost than ARM MCUs. Interestingly enough, Atmel has an ARM based MCU family that it continues to develop. Evidently AVR32 is targeting different applications.