When designing SoCs for IoT applications such as wearable devices or door locks, battery life is a key consideration. Minimizing both dynamic and idle power is important to the system and thus every component in the device must be very efficient in its power usage.
If reprogrammable memory is needed, embedded flash is generally a consideration. Beyond the issues related to cost and time associated with additional processing steps, power consumption is also a drawback. Generally it ranges between 3-7mA for each programming cycle and 500-1000 uA/Mhz for every read access. This can add up rather quickly in terms of impact on system power.
As an alternative, no-mask adder MTP NVM is an option when a small amount of memory to be programmed multiple times is needed. Using MTP NVM can bring substantial savings, especially when the system accesses memory often. MTP NVM should be a consideration for IoT SoC developers who need a low-power solution for programming small amounts of memory multiple times. The MTP NVM can be used either alone or in combination with embedded flash when a portion of the memory is read and programmed often.
As seen in Table 1, MTP NVM uses ~50X less current to write and erase a small amount of data than embedded flash and reads with ~10X lower current. MTP NVM uses Fowler-Nordheim Tunneling, which is inherently more power-efficient than the hot carrier injection embedded flash uses. Synopsys’ DesignWare® MTP NVM IP operates from a single core supply voltage, with some IP reading down to 0.9V, reducing power consumption even further.