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 238
UG585 (v1.11) September 27, 2016
Chapter 8: Timers
8.2 CPU Private Timers and Watchdog Timers
The CPU private timers and watchdog timers are fully documented in the Cortex-A9 MPCore
Technical Requirements Document, sections 4.1 and 4.2 (see Appendix A, Additional Resources).
Both the timer and watchdog blocks have the following features:
• 32-bit counter that generates an interrupt when it reaches zero
• 8-bit prescaler to enable better control of the interrupt period
• Configurable single-shot or auto-reload modes
• Configurable starting values for the counter
8.2.1 Clocking
All private timers and watchdog timers are always clocked at 1/2 of the CPU frequency (CPU_3x2x).
8.2.2 Interrupt to PS Interrupt Controller
The interrupts sent to the interrupt controller are described in section 7.2.2 CPU Private Peripheral
Interrupts (PPI).
8.2.3 Resets
The time and watchdog resets are sent to the PS reset subsystem, see section 26.3 Reset Effects.
8.2.4 Register Overview
A register overview of the CPU private and watchdog timers is provided in Table 8-1.
Table 8-1: CPU Private Timers Register Overview
Function Name Overview
CPU Private Timers
Reload and current values
Timer Load
Timer Counter
Values to be reloaded into the decrementer.
Current value of the decrementer.
Control and interrupt
Timer Control
Timer Interrupt
Enable, auto reload, IRQ, prescaler, interrupt status.
CPU Private Watchdogs (AWDT 0 and 1)
Reload and current values
Watchdog Load
Watchdog Counter
Values to be reloaded into the decrementer.
Current value of the decrementer.
Control and interrupt
Watchdog Control
Watchdog Interrupt
Enable, Auto reload, IRQ, prescaler, interrupt status.
(this register cannot disable watchdog)