18.104.22.168 DPLLs, DLLs
For more information, see:
- Power, Reset, and Clock Management / Clock Management Functional / Internal Clock Sources / Generators / Generic DPLL Overview Section
- Display Subsystem / Display Subsystem Overview section of the Device TRM.
To generate high-frequency clocks, the device supports multiple on-chip DPLLs controlled directly by the PRCM module. They are of two types: type A and type B DPLLs.
- They have their own independent power domain (each one embeds its own switch and can be controlled as an independent functional power domain)
- They are fed with ALWAYS ON system clock, with independent control per DPLL.
The different DPLLs managed by the PRCM are listed below:
- DPLL_MPU: It supplies the MPU subsystem clocking internally.
- DPLL_IVA: It feeds the IVA subsystem clocking.
- DPLL_CORE: It supplies all interface clocks and also few module functional clocks.
- DPLL_PER: It supplies several clock sources: a 192-MHz clock for the display functional clock, a 96-MHz functional clock to subsystems and peripherals.
- DPLL_ABE: It provides clocks to various modules within the device.
- DPLL_USB: It provides 960M clock for USB modules (USB1/2/3/4).
- DPLL_GMAC: It supplies several clocks for the Gigabit Ethernet Switch (GMAC_SW).
- DPLL_DSP: It feeds the DSP Subsystem clocking.
- DPLL_GPU: It supplies clock for the GPU Subsystem.
- DPLL_DDR: It generates clocks for the two External Memory Interface (EMIF) controllers and their associated EMIF PHYs.
- DPLL_PCIE_REF: It provides reference clock for the APLL_PCIE in PCIE Subsystem.
- APLL_PCIE: It feeds clocks for the device Peripheral Component Interconnect Express (PCIe) controllers.
The following DPLLs are controlled by the clock manager located in the always-on Core power domain (CM_CORE_AON):
- DPLL_MPU, DPLL_IVA, DPLL_CORE, DPLL_ABE, DPLL_DDR, DPLL_GMAC, DPLL_PCIE_REF, DPLL_PER, DPLL_USB, DPLL_DSP, DPLL_GPU, APLL_PCIE_REF.
For more information on CM_CORE_AON and CM_CORE or PRCM DPLLs, see the Power, Reset, and Clock Management (PRCM) chapter of the Device TRM.
The following DPLLs are not managed by the PRCM:
- DPLL_VIDEO1; (It is controlled from DSS)
- DPLL_HDMI; (It is controlled from DSS)
- DPLL_DEBUG; (It is controlled from DEBUGSS)
- DPLL_USB_OTG_SS; (It is controlled from OCP2SCP1)
For more information for not controlled from PRCM DPLL’s see the related chapters in TRM.