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Diffstat (limited to 'doc/POWER.txt')
| -rw-r--r-- | doc/POWER.txt | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/doc/POWER.txt b/doc/POWER.txt new file mode 100644 index 0000000000..0abbbe48e8 --- /dev/null +++ b/doc/POWER.txt @@ -0,0 +1,62 @@ +Time to Sleep +============= +USB suspend no activity on USB line for 3ms +No Interaction no user interaction + matrix has no change + matrix has no switch on + + +AVR Power Management +==================== + +V-USB suspend + USB suspend + http://vusb.wikidot.com/examples + +MCUSR MCU Status Register + WDRF Watchdog Reset Flag + BORF + EXTRF + PORF Power-on Reset Flag + +SMCR Sleep Mode Control Register + SE Sleep Enable + SM2:0 + #define set_sleep_mode(mode) \ + #define SLEEP_MODE_IDLE (0) + #define SLEEP_MODE_ADC _BV(SM0) + #define SLEEP_MODE_PWR_DOWN _BV(SM1) + #define SLEEP_MODE_PWR_SAVE (_BV(SM0) | _BV(SM1)) + #define SLEEP_MODE_STANDBY (_BV(SM1) | _BV(SM2)) + #define SLEEP_MODE_EXT_STANDBY (_BV(SM0) | _BV(SM1) | _BV(SM2)) + + +ACSR Analog Comparator Control and Status Register + To disable Analog Comparator + ACSR = 0x80; + or + ACSR &= ~_BV(ACIE); + ACSR |= _BV(ACD); + + ACD: Analog Comparator Disable + When this bit is written logic one, the power to the Analog Comparator is + switched off. This bit can be set at any time to turn off the Analog + Comparator. This will reduce power consumption in Active and Idle mode. + When changing the ACD bit, the Analog Comparator Interrupt must be disabled + by clearing the ACIE bit in ACSR. Otherwise an interrupt can occur when + the bit is changed. + +DIDR1 Digital Input Disable Register 1 + AIN1D + AIN0D + When this bit is written logic one, the digital input buffer on the AIN1/0 pin is disabled. The corresponding PIN Register bit will always read as zero when this bit is set. When an analog signal is applied to the AIN1/0 pin and the digital input from this pin is not needed, this bit should be written logic one to reduce power consumption in the digital input buffer. + + +PRR Power Reduction Register + PRTWI + PRTIM2 + PRTIM0 + PRTIM1 + PRSPI + PRUSART0 + PRADC |