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AT91SAM9R64 Datasheet, PDF (228/911 Pages) ATMEL Corporation – Thumb Microcontrollers | |||
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24.5.5
Power Management
Three low-power modes are available:
⢠Self-refresh Mode: The SDRAM executes its own Auto-refresh cycle without control of the
SDRAM Controller. Current drained by the SDRAM is very low.
⢠Power-down Mode: Auto-refresh cycles are controlled by the SDRAM Controller. Between
auto-refresh cycles, the SDRAM is in power-down. Current drained in Power-down mode is
higher than in Self-refresh Mode.
⢠Deep Power-down Mode: (Only available with Mobile SDRAM) The SDRAM contents are
lost, but the SDRAM does not drain any current.
The SDRAM Controller activates one low-power mode as soon as the SDRAM device is not
selected. It is possible to delay the entry in self-refresh and power-down mode after the last
access by programming a timeout value in the Low Power Register.
228 AT91SAM9R64/RL64 Preliminary
6289AâATARMâ15-Jan-08
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