20
Cyclone for ARM devices User Manual
Cyclone for ARM
®
devices
3.12
JTAG Daisy Chain
The Cyclone for ARM devices supports processors in a JTAG daisy chain
configuration. This type of configuration is desirable if the user wants to share
a single debug connector across multiple JTAG devices.
To start, it is required that the user selects the JTAG communications mode in
the Cyclone Image Creation Utility (see
Section 5.1 - Create A Stand-Alone
). Afterwards, the daisy chain settings are
configured by clicking on the "Advanced" button in the Cyclone Image
Creation Utility. A new dialog will appear, allowing the user to specify their
exact daisy chain setup.
Figure 3-16: Daisy Chain Setup Dialog
As an example, consider a daisy chain containing two devices (TAP #0 and
TAP #1) and both devices have a 4-bit JTAG IR. The following settings would
access the first device in the chain (TAP #0):