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 623
UG585 (v1.11) September 27, 2016
Chapter 21: Programmable Logic Description
Between 25–50% of all slices can use their LUTs as distributed 64-bit RAM, as 32-bit shift register
(SRL32), or as two 16-bit shift registers (SRL16). Modern synthesis tools take advantage of these
highly efficient logic, arithmetic, and memory features.
For more details on Configuration Logic Blocks, see UG474
, 7 Series FPGAs Configurable Logic Block
User Guide.
21.2.2 Clock Management
Some of the key highlights of the clock management architecture include:
• High-speed buffers and routing for low-skew clock distribution
• Frequency synthesis and phase shifting
• Low-jitter clock generation and jitter filtering
Each Zynq-7000 AP SoC device has up to eight clock management tiles (CMTs), each consisting of
one mixed-mode clock manager (MMCM) and one phase-locked loop (PLL).
Mixed-Mode Clock Manager and Phase-Locked Loop
The mixed-mode clock manager (MMCM) and the phase-locked loop (PLL) share many
characteristics. Both can serve as a frequency synthesizer for a wide range of frequencies and as a
jitter filter for incoming clocks. At the center of both components is a voltage-controlled oscillator
(VCO), which speeds up and slows down depending on the input voltage it receives from the phase
frequency detector (PFD).
There are three sets of programmable frequency dividers: D, M, and O. The pre-divider D
(programmable by configuration and afterwards via Dynamic Configuration Port (DRP)) reduces the
input frequency and feeds one input of the traditional PLL phase/frequency comparator. The
feedback divider M (programmable by configuration and afterwards via DRP) acts as a multiplier
because it divides the VCO output frequency before feeding the other input of the phase
comparator. The values of D and M must be chosen appropriately to keep the VCO within its
specified frequency range.
The VCO has eight equally-spaced output phases (0°,45°, 90°, 135°, 180°, 225°, 270°, and 315°). Each
can be selected to drive one of the output dividers (six for the PLL, O0 to O5, and seven for the
MMCM, O0 to O6), each programmable by configuration to divide by any integer from 1 to 128.
The MMCM and PLL have three input-jitter filter options: Low-bandwidth mode which has the best
jitter attenuation; high-bandwidth mode, which has the best phase offset; and optimized mode,
which allows the tools to find the best setting.
MMCM Additional Programmable Features
The MMCM can have a fractional counter in either the feedback path (acting as a multiplier) or in one
output path. Fractional counters allow non-integer increments of
1/8 and can thus increase
frequency synthesis capabilities by a factor of eight.