Functional Description Of The Scan Manager; Configuring Hps I/O Scan Chains - Altera Cyclone V Device Handbook

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2013.12.30

Functional Description of the Scan Manager

The scan manager serves the following two purposes:

• Configuring HPS I/O Scan Chains

• Communicating with the JTAG TAP Controller
Related Information
• Configuring HPS I/O Scan Chains
• Communicating with the JTAG TAP Controller
Configuring HPS I/O Scan Chains
The HPS I/O pins are configured through a series of scan chains.
I/O pin configuration involves such steps as setting the I/O standard and drive strength for each I/O bank.
After a cold reset, all the I/O scan chains in the HPS must be configured prior to being used to communicate
with external devices.
Software uses the scan manager to write configuration data to the scan chains. Separate I/O configuration
data files for FPGA and HPS are generated by the Quartus
the FPGA portion of the system-on-a-chip (SoC) device is assembled. The HPS configuration data is written
to the scan manager by software.
Before configuring a specific I/O bank, the corresponding scan chain must be enabled by writing to the bits
in en register. The scan manager must not be active during this process. Software reads the active bit of
stat register to determine the scan manager state.
Alternatively, when the FPGA JTAG TAP controller receives the CONFIG_IO JTAG instruction, the control
block enters CONFIG_IO mode. When the control block is in CONFIG_IO mode, the controller can override
the scan manager JTAG-AP and configure the HPS I/O pins. The CONFIG_IO instruction configures all
configurable I/O pins in the SoC device including the FPGA I/O pins and the HPS I/O pins. The FPGA and
HPS portions of the device must both be powered on to execute the CONFIG_IO instruction. External logic
connected to the FPGA JTAG pins sends the CONFIG_IO instruction, which provides I/O configuration
data for all FPGA and HPS I/O pins. While CONFIG_IO mode is active, the HPS is held in cold reset to
prevent software from potentially interfering with the I/O configuration.
Related Information
• Scan Manager Address Map and Register Definitions
• System Manager
The HPS I/O pins need to be frozen before configuring them. For more information, refer to the System
Manager chapter in the Cyclone V Device Handbook, Volume 3.
• System Manager
The HPS I/O pins need to be frozen before configuring them. For more information, refer to the System
Manager chapter.
Scan Manager
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on page 15-5
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Functional Description of the Scan Manager
on page 15-6
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II software when the configuration image for
on page 15-8
15-5
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