ULINK: Problems to JTAG-chain Infineon XC16x/XC2xxx/XE16x devices

Information in this knowledgebase article applies to:

• ULINK2 with Infineon XC16x or XC2xxx or XE16x devices

QUESTION

Is it possible to build one JTAG chain with multiple Infineon XC16x or XC2xxx or XE16x devices to debug or program them with just one JTAG interface?

ANSWER

Unfortunately, this is not possible. In principle, the JTAG specification allows chaining of multiple JTAG devices as we have outlined in our ULINK2 User's Guide . However, the Infineon implementation of the JTAG interface does not allow this. All Infineon XC16x, XC2xxx and XE16x devices interpret the first 4 bits that are shifted into JTAG DR register immediately as a command. If multiple JTAG devices are chained, there are a number of bypass bits that need to be shifted through a DR register before the DR register value is evaluated.

Because of this, you need to provide an extra JTAG connector for each of your Infineon XC16x, XC2xxx and XE16x device in order to download code or debug your application.

MORE INFORMATION

• Refer to Chaining Multiple Targets in the ULINK2 User's Guide.

SEE ALSO

• ULINK: CHAINING JTAG DEVICES

Last Reviewed: Tuesday, April 4, 2017