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 650
UG585 (v1.11) September 27, 2016
Chapter 22: Programmable Logic Design Guide
RAM can be used at lower energy cost than processor caches. Table 22-1 summarizes the
approximate energy cost for various functions implemented on both the A9 processor and the 7
series programmable logic.
Typically, the energy cost to read or write external DDR memory is roughly the same and much larger
than the operation cost. As a consequence the energy required by functions which require even a
small percentage of external access is dominated by the energy cost of the external access and the
total cost will be the same in both PL and CPU implementations. Thus a key to minimizing energy
cost is to localize data movement to the PL. If space allows, rather than storing data structures off
chip, store them in OCM, BRAM, LUTRAM or flip-flops and avoid the use of unnecessary storage. This
approach might require code to be restructured to avoid the use of unnecessary buffers.
22.2.5 Real Time Offload
The ARM A9 CPUs are optimized for application processing rather than real-time response and are
often running an operating system such as Linux. The PL can be used augment the A9s with excellent
real time response.
MicroBlaze Assisted Real Time Processing
One or more MicroBlaze processors can be used to as microcontrollers to manage reatime events.
MicroBlaze offers excellent real-time response and can be dedicated to particular tasks. MicroBlaze
controllers can typically use a few block RAMs, approximately 2,000 LUTs, and run at 100-200 MHz.
Interrupt response times are in the 10s of clocks. Alternately the MicroBlaze can poll for events which
can be serviced in just a few clocks. Code can be written in C or for ultimate real time control in
assembly. Unlike the Cortex-A9 CPUs, MicroBlaze has a fixed execution pipeline and offers
predictable response times. For many applications a PicoBlaze processor might be adequate and
uses just a few hundred LUTs.
Table 22-1: Estimated Energy Costs for Common Operations
Operation
PL
Resource
ARM A9
Resource
ARM A9 energy/OP
(pico Joules or
mW/GOP/sec)
PL energy/OP
(pico Joules op
mW/GOP/sec)
Logical Op of 2 var LUT/FF ALU 1.3
32-bit ADD LUT/FF ALU 1.3
16x16 Mult DSP ALU 8.0
32-bit Read/Write register LUTRAM L1 1.4
32-bit Read/Write AXI register LUT/FF AXI 30
32-bit Read/Write local RAM BRAM L2 23.7/17.2
32-bit Read/Write OCM AXI/OCM CPU/OCM 44
32-bit Read/Write DDR3 AXI/DDR CPU/DDR 541/211
Notes:
1. A9 energy costs estimated from ARM power indicative benchmarks.
2. PL Energy costs for custom programmable logic functions are estimated using the Xilinx XPE power estimator
http://www.xilinx.com/ise/power_tools/license_7series.htm
.