all the information that it reads from the platform to create a custom platform
configuration. However, sometimes it is not possible for DS-5 to read all of the
information that it needs from a platform. There could be many reasons for this:
- JTAG routing or security devices might prevent DS-5 from
discovering details of physical JTAG devices.
- Debug or trace might be partially or fully disabled.
- Devices might be powered down, or their clocks might be disabled. This can make
devices unresponsive to requests for information, and can affect individual devices,
entire clusters, or all the devices in a ROM table.
- ROM tables might be missing, incomplete, or at the wrong address.
- Integration Test registers might not be fully implemented, or their operation might
be limited by other devices.
- The platform might contain unsupported devices.
Autoconfiguring the platform might cause the target to stop and reset. If you
do not want to reset the target, you can manually create the platform configuration
To manually create the platform configuration:
- Select Advanced platform detection or manual creation from the
New Platform dialog box, as shown in 10.6 Creating a new platform configuration.
- Provide the necessary topology information using PCE in DS-5.
- This creates a new System Description File (.sdf). Save and build the sdf file.
To provide the necessary topology information using PCE, refer to the topology
diagram for your platform to know how to describe the configuration. When you know the
topology, you can add the components using these steps:
- Create the JTAG scan chain, by adding all the devices that are on the scan
chain. You can drag-and-drop devices to the scan chain from the device panel into the
Devices folder in the PCE view. The
devices must be in the right order on the JTAG scan chain.
can also add custom or unsupported devices to the JTAG scan chain. To add a
custom device, right-click on the Devices
folder and select Add Custom Device. You
must specify the correct JTAG Instruction Register (IR) length for these
devices. You can provide any name for the custom device. You cannot debug a
custom device. However, adding the custom device in the correct order and with
the correct length enables you to debug the supported devices in the same scan
chain. It is not possible to consolidate unknown devices on the scan chain. For
example two custom devices with instructions lengths of 4 and 5 bits cannot be
replaced by a single custom device of instruction length 9 bits.
- Before you can add CoreSight devices or Cortex processors to the device
hierarchy, you must add a CoreSight Debug Access Port (DAP), for example ARMCS-DP.
For each DAP, you must add the CoreSight Memory Access Ports (AP) that you need, for
example CSMEMAP. You must specify the correct index and type of each AP.
- Add the Cortex processors and CoreSight devices to the correct AP on the correct DAP. To do
this, drag-and-drop them from the devices panel into the correct AP. Since the
CoreSight devices are memory-mapped, you can add them in any order. However, you
must ensure that the device type and ROM table base address are correct.
- Add the component connection information to specify how the devices are connected to each
other. 10.7 Editing a platform configuration in the PCE describes this.
If you do not need trace support, then you do not need to provide details and topology
for trace devices. DS-5 will read as much information as it can. You must always review the
information that has been collected before deciding what further information is
necessary. If DS-5
fails to read information, it might be an indication of a deeper problem than missing
For example, if DS-5 fails
to discover the base addresses because the devices are completely powered down, it might
not be possible to provide debug support even if the information is provided manually.
This is because the powered down devices are not responsive to the debugger. You might
need to perform other operations, such as enabling clocks or powering processor
clusters, before debug and trace are possible.