Product Brief
ARM7 flash MCU goes for under $3
marty Gold10/19/2004 2:44 PM EDT
The AT91SAM7S32 and the AT91SAM7S64 are the first members of this family of small pin-count Smart ARM7 Microcontrollers (SAM7S) with flash densities of 32 kBytes, and 64 kBytes. The S32 and S64 have 8 Kbytes and 16 Kbytes of on-chip SRAM respectively. In quantities of 10k, the AT91SAM7S32 is available in a 48-lead LQFP package at a suggested resell of $2.90 and the AT91SAM7S64 in a 64-lead LQFP package, at $4.05.
Two additional devices, the 128 kBytes and 256 kBytes AT91SAM7S128 and AT91SAM7S256, are planned for availability at the end of this year. The S128 and S256 will have 32 Kbytes and 64 Kbytes of on-chip SRAM respectively. Pricing is expected to be $5.95 for the S128 and $7.85 for the S256, both in 10K quantities.
Besides a jump in real-time performance over 8-bit microcontrollers, they are the world's first 32-bit micro-controllers to integrate a complete set of secure operation functions including a watchdog clocked by an on-chip RC oscillator, power supply monitors and hardware protection of the flash memory.
The AT91SAM7 microcontrollers are supported by low-cost development tools, bringing 32-bit real-time pro-cessing power to a wide range of cost-sensitive applications that have until now been limited to 8-bit performance.
The AT91SAM7S series focuses on the drivers for change from 8 to 32 bits, in particular improved deterministic performance for real-time applications. It achieves single-cycle instruction access from embedded Flash (a pre-requisite for deterministic performance) at 27 MIPS. 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 (another Atmel enhancement of the basic ARM provision) enable single-cycle bit manipulation, obviating the need for masked read-modify-write sequences.
The porting and qualification of legacy code is a significant task for 8-bit microcontroller users migrating to a 32-bit MCU. To facilitate application development, the AT91SAM7S products embeds powerful debug capabilities centered around a JTAG In-Circuit-Emulation interface and complemented with on-chip hardware like misaligned address detection and watchdog deactivation during debug. Atmel supplies a kit including an evaluation board, JTAG-ICE interface, project examples and development tools identical to those for 8-bit microcontrollers, thereby reducing the learning curve.
The high level of functional integration of the AT91SAM7S microcontrollers 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. The on-chip voltage regulator enables single-supply operation at 3.3V.
The embedded Flash memory can be programmed in-system via the JTAG-ICE 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 hardware security bit that disables its external visibility, and sixteen lock bits that secure each of its 4K-byte lock regions. Its integrated brownout detector coupled with power-on-reset guards against accidental or deliberate code corruption during power-down. These are essential to preserve the confidentiality of application code.
Target applications for the AT91SAM7S series include appliance control, utility metering, security systems, data loggers, USB-based mobile phone and PC accessories.
Jacko Wilbrink, Atmel's ARM-based product manager commented, "The SAM7S-series are the first products of an exciting new family of Smart ARM Microcontrollers that fill the gap between 8-bit microcontroller cost and 32-bit real-time performance. They provide ease and speed of application development based on familiar features with enhanced performance and security at an extremely attractive price."
In quantities of 10k, the AT91SAM7S32 is available in a 48-lead LQFP package at a suggested resell of $2.90 and the AT91SAM7S64 in a 64-lead LQFP package, at $4.05.
For more information, visit www.atmel.com



