Last week, Bits & Pieces discussed Atmel’s Peripheral Event System in the context of the recently launched SAM D20 microcontroller (MCU) lineup. Today, we’re getting up close and personal with SERCOM (Serial Communication Module) on the SAM D20 which can be configured to support UART/USART, SPI or I2C.
“SERCOM offers immense flexibility when embarking on a design since it allows devs to configure available interfaces as needed. Essentially, there are two very important benefits to this approach,” explained Andreas Eieland, Sr. Product Marketing Manager, Atmel.
“Firstly, you no longer need to trawl through microcontroller specifications looking for a device with the number of types of serial interfaces you require. Not only does this save a lot of time but it also allows you to adopt a single microcontroller for a number of similar designs where the interfaces required may differ slightly and you no longer have to buy a device that has five UARTS because you need three SPIs.”
According to Eieland, another benefit of Atmel’s SERCOM relates to designing the PCB. By choosing the interface type to coincide with the location of any supporting interface components or interconnect on the PCB, engineers can ensure more efficient PCB routing that is not only potentially shorter, but also avoids any long signal paths past electrically noisy components.
“This is made possible by having multiple SERCOM modules and the fact that each SERCOM module boasts multiple pin connection options. Remember, Atmel’s SAM D20 device supports I2C fast mode of up to 400 kHz while SPI and UART are capable of up to 24 Mb/s transfer speeds,” he continued.
“Plus, the serial communication modules all are connected to the Peripheral Event System – facilitating peripheral cooperation without CPU intervention. Each SERCOM module is also capable of being reconfigured by software into another interface type on-the-fly.”