User manual
Table Of Contents
- Zynq-7000 All Programmable SoC
- Table of Contents
- Ch. 1: Introduction
- Ch. 2: Signals, Interfaces, and Pins
- Ch. 3: Application Processing Unit
- Ch. 4: System Addresses
- Ch. 5: Interconnect
- Ch. 6: Boot and Configuration
- Ch. 7: Interrupts
- Ch. 8: Timers
- Ch. 9: DMA Controller
- Introduction
- Functional Description
- DMA Transfers on the AXI Interconnect
- AXI Transaction Considerations
- DMA Manager
- Multi-channel Data FIFO (MFIFO)
- Memory-to-Memory Transfers
- PL Peripheral AXI Transactions
- PL Peripheral Request Interface
- PL Peripheral - Length Managed by PL Peripheral
- PL Peripheral - Length Managed by DMAC
- Events and Interrupts
- Aborts
- Security
- IP Configuration Options
- Programming Guide for DMA Controller
- Programming Guide for DMA Engine
- Programming Restrictions
- System Functions
- I/O Interface
- Ch. 10: DDR Memory Controller
- Introduction
- AXI Memory Port Interface (DDRI)
- DDR Core and Transaction Scheduler (DDRC)
- DDRC Arbitration
- Controller PHY (DDRP)
- Initialization and Calibration
- DDR Clock Initialization
- DDR IOB Impedance Calibration
- DDR IOB Configuration
- DDR Controller Register Programming
- DRAM Reset and Initialization
- DRAM Input Impedance (ODT) Calibration
- DRAM Output Impedance (RON) Calibration
- DRAM Training
- Write Data Eye Adjustment
- Alternatives to Automatic DRAM Training
- DRAM Write Latency Restriction
- Register Overview
- Error Correction Code (ECC)
- Programming Model
- Ch. 11: Static Memory Controller
- Ch. 12: Quad-SPI Flash Controller
- Ch. 13: SD/SDIO Controller
- Ch. 14: General Purpose I/O (GPIO)
- Ch. 15: USB Host, Device, and OTG Controller
- Introduction
- Functional Description
- Programming Overview and Reference
- Device Mode Control
- Device Endpoint Data Structures
- Device Endpoint Packet Operational Model
- Device Endpoint Descriptor Reference
- Programming Guide for Device Controller
- Programming Guide for Device Endpoint Data Structures
- Host Mode Data Structures
- EHCI Implementation
- Host Data Structures Reference
- Programming Guide for Host Controller
- OTG Description and Reference
- System Functions
- I/O Interfaces
- Ch. 16: Gigabit Ethernet Controller
- Ch. 17: SPI Controller
- Ch. 18: CAN Controller
- Ch. 19: UART Controller
- Ch. 20: I2C Controller
- Ch. 21: Programmable Logic Description
- Ch. 22: Programmable Logic Design Guide
- Ch. 23: Programmable Logic Test and Debug
- Ch. 24: Power Management
- Ch. 25: Clocks
- Ch. 26: Reset System
- Ch. 27: JTAG and DAP Subsystem
- Ch. 28: System Test and Debug
- Ch. 29: On-Chip Memory (OCM)
- Ch. 30: XADC Interface
- Ch. 31: PCI Express
- Ch. 32: Device Secure Boot
- Appx. A: Additional Resources
- Appx. B: Register Details
- Overview
- Acronyms
- Module Summary
- AXI_HP Interface (AFI) (axi_hp)
- CAN Controller (can)
- DDR Memory Controller (ddrc)
- CoreSight Cross Trigger Interface (cti)
- Performance Monitor Unit (cortexa9_pmu)
- CoreSight Program Trace Macrocell (ptm)
- Debug Access Port (dap)
- CoreSight Embedded Trace Buffer (etb)
- PL Fabric Trace Monitor (ftm)
- CoreSight Trace Funnel (funnel)
- CoreSight Intstrumentation Trace Macrocell (itm)
- CoreSight Trace Packet Output (tpiu)
- Device Configuration Interface (devcfg)
- DMA Controller (dmac)
- Gigabit Ethernet Controller (GEM)
- General Purpose I/O (gpio)
- Interconnect QoS (qos301)
- NIC301 Address Region Control (nic301_addr_region_ctrl_registers)
- I2C Controller (IIC)
- L2 Cache (L2Cpl310)
- Application Processing Unit (mpcore)
- On-Chip Memory (ocm)
- Quad-SPI Flash Controller (qspi)
- SD Controller (sdio)
- System Level Control Registers (slcr)
- Static Memory Controller (pl353)
- SPI Controller (SPI)
- System Watchdog Timer (swdt)
- Triple Timer Counter (ttc)
- UART Controller (UART)
- USB Controller (usb)
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 325
UG585 (v1.11) September 27, 2016
Chapter 10: DDR Memory Controller
5. Assert reg_ddrc_soft_rstb to reset the controller. When the controller is taken out of reset, it
re-initializes the DRAM. During initialization, the mode register values updated in step 4 are
written to DRAM. Anytime after de-asserting reset, go to step 6.
6. Take the controller out of self refresh by de-asserting reg_ddrc_selfref_en.
Note: This sequence can be followed in general for changing DDRC settings, in addition to just clock
frequencies.
Note: DRAM content preservation is not guaranteed when the controller is reset.
10.9.3 Power Down
Enable power down mode in the Master Control register, ddrc_ctrl. Once enabled, the DDRC
automatically puts the DRAM into pre-charge all power down after the programmed number of idle
cycles (DDRC_param_reg1.reg_ddrc_powerdown_to_x32).
A refresh request brings the DRAM out of power down. It goes back into power down after the idle
period.
Any transaction brings the DRAM out of power down automatically.
Clearing the power down enable bit also brings the DRAM out of power down.
10.9.4 Deep Power Down
Note: Deep power down only applies to LPDDR2 mode.
Set deep_pwrdwn_reg.deeppowerdown_en=1. The DDRC puts the DRAM into deep power down as
soon as the transaction buffers are empty. If transactions keep arriving the DDRC never puts the
DRAM into deep power down.
deep_pwrdwn_reg.deeppowerdown_en must be reset to 0 to take DRAM out of deep power down
mode. During deep power down exit, the controller performs automatic DRAM initialization.
In LPDDR2, once deep_pwrdwn_reg.deeppowerdown_en is reset to 0, there is a wait period
(determined by register reg_ddrc_deeppowerdown_to_x1024) before the DRAM comes out of deep
power down. The value from the spec for this register is 500 us.
Note that any command that comes in while the DRAM is in deep power down mode is stored in the
CAM and is processed after deep power down exit and DRAM re-initialization.
10.9.5 Self Refresh
Set the Self Refresh Request bit in the Master Control register, ddrc_ctrl. The DDRC puts the DRAM
into self refresh as soon as the transaction buffers are empty.
Software must ensure that no transactions arrive. If transactions keep arriving the DDRC never puts
the DRAM into self refresh.
The first valid transaction brings the DRAM out of self refresh.