Question
On the ARM7 based ADuC devices, debugging and downloading to Flash was via
JTAG. On the
AduCM360, JTAG is replaced with Serial Wire Debug. What are the differences
between Serial
Wire Debug and JTAG? Do I need to get new tools, new emulator?
Answer
Serial Wire DeBug (SWD) is an alternative to JTAG for debug. It was preferred
to JTAG because of its low pin requirement (2). The tools currently used for
the ARM7 based families also support serial wire debug; there is no need to
purchase new emulator.
In terms of communication speed, SWD is a fast as JTAG. The speed limitation
comes from the on-chip Flash access time and not from the debug port.