Multi-voltage Design Apr

In the advanced process, in order to reduce the chip power consumption, often using muti-voltage design, in a chip within a number of power domain, different domain with different voltages, and sometimes some of the power domain to switch off, So that it goes to sleep, to achieve the purpose of reducing power consumption.

In multi-voltage design, there are some common issues that are documented as follows:

1, for design with multiple power domain, some of which are shut down, called Off-domain, and some domain is always power, called On-domain;on-domain Power is always- On, and the Off-domain power is transferred from always-on power to power switch, and when power switch is turned off, Off-domain power is disconnected and goes into low-power mode, but sometimes I We want to save the state before the Off_domain shutdown, which requires the retention cell, the normal cell has only one power pin and one ground pin, and the retention cell has two power pins and a Ground pin, two power pins are primary power (on Off-power, will be turned off) and secondary power (connected to On-power, always have power), typical retention cell The power structure is as follows:

When the off-power is turned off,

Multi-voltage Design Apr