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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 673
UG585 (v1.11) September 27, 2016
Chapter 24: Power Management
24.3 Programming Guides
24.3.1 System Modules
The power management features of the Zynq-7000 AP SoC's system modules are described in detail
in their respective chapter. Please refer to Table 24-4 for an overview and further references.
24.3.2 Peripherals
The primary peripheral power management mechanisms are clock scaling and gating. Chapter 25,
Clocks describes the system clocks and how they can be controlled through dividers, gates, and
multiplexers. Table 24-2 gives a brief overview of the power management capabilities for the device
subsystems. Every peripheral includes clock gating and, in some cases, low-power states.
With all these pieces working together, the system-level sleep mode is defined. (Refer to section
24.4 Sleep Mode.) In sleep mode the whole chip enters a low-power state, waiting for a wake-up
event to continue operation.
Peripheral Clock Gating
For peripherals with an independent clock domain for the interconnect, disable the device's
interconnect clock last and enable it first to avoid accesses to inaccessible register areas. See
Chapter 25, Clocks and the respective chapter for a peripheral for additional details.
Table 24-1: Power Management for System Modules
System Module
Clocked in
Standby Mode
Description
APU Yes See Chapter 3, Application Processing Unit.
SCU (with GIC) Yes See Chapter 3, Application Processing Unit.
L2-Cache Yes See Chapter 3, Application Processing Unit.
Interconnect Yes Clocks are stopped automatically if enabled, refer to
Chapter 25, Clocks.
Peripherals Depends Peripheral used as a wake-up source must be clocked, refer to
Table 24-2.
Table 24-2: Power Management for Peripheral Controls
Peripheral Wake-up Source
Clock Gating Low-Power
Mode
Other Low-Power Modes
PCAP No No None
Timers
Yes
Chapter 8, Timers
Yes
Chapter 25, Clocks
None
DMA Controller No
Yes
Section 9.6 System
Functions
None