Atmel AVR XMEGA AU series, Manual

Page: 109 / 512

109
8331B–AVR–03/12
Atmel AVR XMEGA AU
8.6 Register Description – Sleep
8.6.1 CTRL – Control register
• Bit 7:4 – Reserved
These bits are unused and reserved for future use. For compatibility with future devices, always
write these bits to zero when this register is written.
• Bit 3:1 – SMODE[2:0]: Sleep Mode Selection
These bits select sleep modes according to Table 8-2 on page 109 .
• Bit 0 – SEN: Sleep Enable
This bit must be set to make the MCU enter the selected sleep mode when the SLEEP instruc-
tion is executed. To avoid unintentional entering of sleep modes, it is recommended to write
SEN just before executing the SLEEP instruction and clear it immediately after waking up.
8.7 Register Description – Power Reduction
8.7.1 PRGEN – General Power Reduction register
Bit 7 6 5 4 3 2 1 0
+0x00 – – – – SMODE[2:0] SEN CTRL
Read/Write R R R R R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Table 8-2. Sleep mode
SMODE[2:0] Group Configuration Description
000 IDLE Idle mode
001 — Reserved
010 PDOWN Power-down mode
011 PSAVE Power-save mode
100 — Reserved
101 — Reserved
110 STDBY Standby mode
111 ESTDBY Extended standby mode
Bit 7 6 5 4 3 2 1 0
+0x00 – USB – AES EBI RTC EVSYS DMA PRGEN
Read/Write R R/W R R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0