What is MMMC
MMMC stands for: Multi-Mode Multi Corner
What's a Mode
A mode is defined by a set of clocks, supply voltages, timing constraints, and libraries. It can also have annotation data, such as SDF or parasitics files.
Many chip have multiple modes such as functional modes, test mode, sleep mode, and etc.
What's a Corner
A corner is defined as a set of libraries characterized for process, voltage, and temperature variations.
Corners are not dependent on functional settings; they are meant to capture variations in the manufacturing process, along with expected variations in the voltage and temperature of the environment in which the chip will operate.
For example, In MMMC, we can have 3 different views as shown in the picture above. The turbo mode (left most one) which is high temperature, high frequency and high voltage, we are doing only set up check.
Similarly there is turbo - hold mode (right most one) defined which is lowest temperature, highest frequency and highest voltage. In this mode, we only check for hold.