58.9 Operation and Power Consumption in Low-Power Modes
The SAM9X60 features four low-power modes summarized in the following table. A detailed description of each mode is given in the following sections.
| Low-power Mode | |||||
|---|---|---|---|---|---|
| Backup Mode | ULP1 | ULP0 | Idle | ||
| VDDBU power | ✓ | ✓ | ✓ | ✓ | |
| VDDCORE power | ✗ | ✓ | ✓ | ✓ | |
| SDRAM or DDR power | ✗ | ✓ | ✓ | ✓ | |
| I/O power | ✗ | ✓ | ✓ | ✓ | |
| DDR Self-refresh | – | ✓ | ✓ | ✗ | |
| Main crystal oscillator | – | ✗ | ✗ | ✓ | |
| Main RC oscillator | – | ✗ | ✗ | ✓ | |
| Main clock (MAINCK) | Source (MOSCSEL) | – | Main RC osc. | Main RC osc. | User-defined |
| Status | – | ✗ | ✗ | ✓ | |
| Main system bus clock (MCK) | Source (CSS) | – | MAINCK | User-defined (MD_SLCK, MAINCK, etc.) | User-defined (PLLA, etc.) |
| Status | – | ✗ | ✓ | ✓ | |
| CPU clock (HCLK) | – | ✗ | ✓ | ✓ | |
| ARM926EJ-S state | – | Clocks stopped | WFI | WFI | |
| Mode entry | Use SHDWC to shutdown all power supplies except VDDBU | Context saved in DDR DDR in Self-refresh ULP1 bit | Context saved in DDR DDR in Self-refresh WFI | WFI | |
| Wake-up | Sources | RTC alarm WKUP0 pin |
RTC / RTT alarm USB resume Wake-On-LAN WKUP[13:1] | Any non-masked interrupt | Any non-masked interrupt |
| Event or interrupt sampling clock | MD_SLCK | Asynchronous | User-defined (MCK, periph_clk, etc.) | User-defined (MCK, periph_clk, etc.) | |
| Main system bus clock (MCK) at wake-up | MAINCK (defaults to Main RC osc.) | MAINCK (configured to Main RC osc.) | User-defined | User-defined | |
Note:
- ✓/✗ means either powered/unpowered for a power source, on/off for an oscillator, active/inactive for a clock signal, or in/out of Self-refresh mode for the external SDRAM.