• Renesas has launched the RZ/G3L and RZ/G3SE processors for industrial interfaces, gateways and other connected edge equipment
  • Renesas rates deep-standby power at around 1mW while Linux remains in memory, but that figure applies to the processor rather than the whole device

The fact

Renesas has launched two processors designed for industrial interfaces, gateways and other equipment that runs computing close to where data is produced. The RZ/G3L and RZ/G3SE became available on 10 September alongside evaluation boards. The two chips use compatible pin layouts, allowing manufacturers to use much of the same circuit-board design across different products. The RZ/G3L supports more advanced graphics and video, while the RZ/G3SE is aimed at equipment with simpler display needs.

Renesas says the processors can enter a deep standby mode that uses power at around the 1mW level while keeping Linux in memory. This allows the system to resume without starting the operating system again from scratch. The 1mW figure refers to the processor in deep standby. It does not represent the electricity used by a complete gateway once memory, communications equipment and other components are included.

The assessment

The new standby mode will be most useful in equipment that spends a meaningful amount of time waiting. An industrial gateway that sits idle between tasks may be able to reduce its power use by putting the main processor to sleep and waking it when work arrives.

The 1mW figure does not tell us how much electricity the finished device will save. Other parts of the gateway may need to stay powered so it can remain connected and respond when needed. Designers also have to make sure waking the processor does not make the device too slow for its job.

For BTW readers, the test is simple: does a finished device use less power over a normal day without becoming slower to respond? Measurements from evaluation boards and real products will tell us more than the processor's lowest standby figure on its own.

What to watch

Watch for tests using complete gateways with networking and other components attached. Measurements of total power use, time spent in standby and wake-up speed will show where the new mode saves meaningful energy and where devices need to remain active.