The RAM power control registers are used for configuring the following:
- The RAM sections to be retained during System OFF
- The RAM sections to be retained and accessible during System ON
In System OFF, retention of a RAM section is configured in the RETENTION field of the corresponding register RAM[n].POWER (n=0..7).
In System ON, retention and accessibility for a RAM section is configured in the RETENTION and POWER fields of the corresponding register RAM[n].POWER (n=0..7).
The following table summarizes the behavior of these registers.
| Configuration | RAM section status | |||
|---|---|---|---|---|
| System on/off | RAM[n].POWER.POWER | RAM[n].POWER.RETENTION | Accessible | Retained |
| Off | x | Off | No | No |
| Off | x | On | No | Yes |
| On | Off | Off | No | No |
| On | Off | On | No | Yes |
| On | On | x | Yes | Yes |
The advantage of not retaining RAM contents is that the overall current consumption is reduced.
See chapter Memory for more information on RAM sections.