Things You Should Be Aware Of - Segger J-Link User Manual

6. Choose Project|Options and configure your second scan chain. The following
dialog box shows the configuration for the second ARM core on your target.
7. Start debugging your second core.
Example:
Core #1 Core #2
ARM7TDMI ARM7TDMI-S
ARM7TDMI
ARM7TDMI
ARM7TDM
ARM7TDMI-S ARM7TDMI-S
I-S
Table 5.9: Multicore debugging
Cores to debug are marked in blue.
5.5.3

Things you should be aware of

Multi-core debugging is more difficult than single-core debugging. You should be
aware of the pitfalls related to JTAG speed and resetting the target.
5.5.3.1 JTAG speed
Each core has its own maximum JTAG speed. The maximum JTAG speed of all cores
in the same chain is the minimum of the maximum JTAG speeds.
For example:
Core #1: 2MHz maximum JTAG speed
Core #2: 4MHz maximum JTAG speed
Scan chain: 2MHz maximum JTAG speed
J-Link / J-Trace (UM08001)
TAP number
Core #3
debugger #1
ARM7TDMI 0
0
ARM7TDMI
1
© 2004-2009 SEGGER Microcontroller GmbH & Co. KG
TAP number
debugger #2
1
2
2
87