Specifications

JTAG Multi-Device Configuration
You can configure multiple devices in a JTAG chain.
Pin Connections and Guidelines
Observe the following pin connections and guidelines for this configuration setup:
•
Isolate the CONF_DONE and nSTATUS pins to allow each device to enter user mode independently.
• One JTAG-compatible header is connected to several devices in a JTAG chain. The number of devices
in the chain is limited only by the drive capability of the download cable.
•
If you have four or more devices in a JTAG chain, buffer the TCK, TDI, and TMS pins with an on-board
buffer. You can also connect other Altera devices with JTAG support to the chain.
• JTAG-chain device programming is ideal when the system contains multiple devices or when testing
your system using the JTAG boundary-scan testing (BST) circuitry.
Using a Download Cable
The following figure shows a multi-device JTAG configuration.
Figure 7-19: JTAG Configuration of Multiple Devices Using a Download Cable
TMS TCK
Download Cable
10-Pin Male Header
(JTAG Mode)
TDI
TDO
V
CCPD
V
CCPD
V
CCPD
Pin 1
nSTATUS
nCONFIG
MSEL[4..0]
nCE
GND GND GND
V
CCPGM
V
CCPGM
V
CCPGM
V
CCPGM
V
CCPGM
V
CCPGM
CONF_DONE
V
IO
FPGA Device FPGA Device FPGA Device
1 kΩ
10 kΩ 10 kΩ 10 kΩ 10 kΩ 10 kΩ 10 kΩ
DCLK
TMS TCK
TDI
TDO
nSTATUS
nCONFIG
MSEL[4..0]
nCE
CONF_DONE
DCLK
TMS TCK
TDI
TDO
nSTATUS
nCONFIG
MSEL[4..0]
nCE
CONF_DONE
DCLK
Connect the pull-up
resistor V
CCPD
.
If you only use the JTAG configuration, connect nCONFIG to V
CCPGM
and MSEL[4..0]
to GND. Pull DCLK either high or low, whichever is convenient on your board. If you are
using JTAG in conjunction with another configuration scheme, connect MSEL[4..0],
nCONFIG, and DCLK based on the selected configuration scheme.
The resistor value can vary from 1 kΩ to 10
kΩ. Perform signal integrity analysis to
select the resistor value for your setup.
Related Information
AN 656: Combining Multiple Configuration Schemes
Provides more information about combining JTAG configuration with other configuration schemes.
CONFIG_IO JTAG Instruction
The CONFIO_IO JTAG instruction allows you to configure the I/O buffers using the JTAG port before or
during device configuration. When you issue this instruction, it interrupts configuration and allows you to
Configuration, Design Security, and Remote System Upgrades in Cyclone V Devices
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JTAG Multi-Device Configuration
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2013.06.11