Atmel's latest ARM-based micro brings 32-bit performance to cost-sensitive applications

2005-07-18

Available from DT Electronics, Atmel’s AT91SAM7S microcontrollers, based on the industry-standard ARM7TDMI 32-bit RISC processor, are low-cost microcontrollers with Flash memory capacities ranging from 32K to 256K bytes. Supported by an attractively priced evaluation kit featuring industry-standard development tools, they bring 32-bit processing power to a wide range of cost-sensitive applications that have until now been limited to 8 or 16-bit performance.

The AT91SAM7S series integrates numerous features that facilitate the evolution from 8 or 16 to 32 bits, in particular for embedded real-time control systems. It achieves single-cycle instruction access from embedded Flash at 27 MIPS and offers a 32-bit address space, more than sufficient for its target applications. Its Advanced Interrupt Controller enhances the basic interrupt facilities of the ARM7 processor to give vectored priority interrupt handling in a minimum number of instruction cycles. Its hardware bit set and reset registers enable single-cycle bit manipulation, obviating the need for masked read-modify-write sequences. Its integrated brownout detector coupled with power-on-reset guards against accidental or deliberate code corruption during power-down. Its on-chip voltage regulator enables single-supply operation at 3.3V. All these features are evolutions of typical provisions in the 8 or 16-bit world, at the same time offering significantly improved performance.

The embedded Flash memory can be programmed in-system via the JTAG interface or via a parallel interface on a production programmer just prior to installation. This enables software development to continue until the final phase of hardware assembly and software updates to be incorporated with no disruption to production. The Flash memory contains a security bit that disables its external visibility and sixteen lock bits that secure each of its 4K-byte lock regions. These are essential to preserve the confidentiality of application code.

The rich peripheral set of the AT91SAM7S series includes a USB 2.0 full-speed device port for PC connectivity and a wide variety of communication and control interfaces including an 8-channel 10-bit ADC. Peripheral data controllers provide a DMA function that reduces processor overhead during data transfers between external I/O channels and memory. A parallel I/O controller multiplexes the peripheral I/Os with a set of 32 programmable general-purpose I/O lines thereby reducing the external pin count while providing additional flexibility of access.

A low-cost evaluation kit provides a familiar, industry-standard development environment.