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Diffstat (limited to 'doc/README.Lite5200B_low_power')
| -rw-r--r-- | doc/README.Lite5200B_low_power | 22 |
1 files changed, 0 insertions, 22 deletions
diff --git a/doc/README.Lite5200B_low_power b/doc/README.Lite5200B_low_power deleted file mode 100644 index 5b04fbba72..0000000000 --- a/doc/README.Lite5200B_low_power +++ /dev/null @@ -1,22 +0,0 @@ -Lite5200B wakeup from low-power mode (CONFIG_LITE5200B_PM) ----------------------------------------------------------- - -Low-power mode as described in Lite5200B User's Manual, means that -with support of MC68HLC908QT1 microcontroller (refered to as QT), -everything but the SDRAM can be powered down. This brings -maximum power saving, while one can still restore previous state -quickly. - -Quick overview where U-Boot comes into the picture: -- OS saves device states -- OS saves wakeup handler address to physical 0x0, puts SDRAM into - self-refresh and signals to QT, it should power down the board -- / board is sleeping here / -- someone presses SW4 (connected to QT) -- U-Boot checks PSC2_4 pin, if QT drives it down, then we woke up, - so get SDRAM out of self-refresh and transfer control to OS - wakeup handler -- OS restores device states - -This was tested on Linux with USB and Ethernet in use. Adding -support for other devices is an OS issue. |