Designing a board management controller with Atmel’s SAM D20 MCU

A board management controller (BMC) is a platform that monitors the physical state of an enclosure or system using physical sensors.  The sensors track a number of critical variables including humidity, temperature, power-supply voltage, fan speed, communications parameters and operating system functions.

Unsurprisingly, a BMC typically operates independently of the main system (out of band). Key design considerations of a board management controller include connectivity; multiple serial interfaces to communicate with various sensors and administrative terminal; low-power operation in low power mode to protect against system as well power outages; and continuous operation during system outages for uninterrupted system management.

A number of Atmel hardware components can be used to design a board management controller, including the SAM D20 ARM Cortex-M0+ (ARM) based MCU, the SHA204 Authentication IC (for security), 30TS temperature sensor and AT24/AT25 Serial EEPROM.

“The SAM D20 offers versatile connectivity options, low-power operation and a high level of integration to reduce BOM cost. Indeed, there are 6 SERCOM modules, each configurable as USART, I2C or SPI for sensors and terminal communication, thereby facilitating smaller packages and easier PCB layout,” Atmel engineer Bob Martin told Bits & Pieces. “Meanwhile, integrated 12-bit 300ksps ADC with gain stage removes the need for external components to monitor local battery voltage, as low-power operation ensures protection against system/power outages.”

Martin also noted that Atmel’s SAM D20 ensures high reliability even under system outages, with the platform featuring integrated 32-bit Cyclic Redundancy Check (CRC) of Flash, EEPROM emulation, as well as SRAM and integrated memory BIST (MBIST) to execute production testing of internal memories.

On the software side, the SAM D20 offers users access to an expansive array of tools and comprehensive ecosystem including Atmel Studio 6 (free IDE with compiler), Atmel’s Software Framework (ASF) with free SW libraries of production-ready source code. There is also the Atmel Gallery and the SAMD20 Xplained Pro Kit which boasts a built-in programmer and debugger with connectors for expansion wings.

Additional information about Atmel’s SAMD 20 MCU can be found here.