SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 219

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

12.5.3.1
12.5.4
12.5.5
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
FPB (Flash Patch Breakpoint)
DWT (Data Watchpoint and Trace)
SW-DP and JTAG-DP Selection Mechanism
When the Serial Wire Debug Port is active, TDO/TRACESWO can be used for trace. The asyn-
chronous TRACE output (TRACESWO) is multiplexed with TDO. So the asynchronous trace
can only be used with SW-DP, not JTAG-DP.
Table 12-2.
SW-DP or JTAG-DP mode is selected when JTAGSEL is low. It is not possible to switch directly
between SWJ-DP and JTAG boundary scan operations. A chip reset must be performed after
JTAGSEL is changed.
Debug port selection mechanism is done by sending specific SWDIOTMS sequence. The JTAG-
DP is selected by default after reset.
The FPB:
The FPB unit contains:
The DWT contains four comparators which can be configured to generate the following:
Pin Name
TMS/SWDIO
TCK/SWCLK
TDI
TDO/TRACESWO
• Switch from JTAG-DP to SW-DP. The sequence is:
• Switch from SWD to JTAG. The sequence is:
• Implements hardware breakpoints
• Patches code and data from code space to system space.
• Two literal comparators for matching against literal loads from Code space, and remapping to
• Six instruction comparators for matching against instruction fetches from Code space and
• Alternatively, comparators can also be configured to generate a Breakpoint instruction to the
• PC sampling packets at set intervals
• PC or Data watchpoint packets
a corresponding area in System space.
remapping to a corresponding area in System space.
processor core on a match.
– Send more than 50 SWCLKTCK cycles with SWDIOTMS = 1
– Send the 16-bit sequence on SWDIOTMS = 0111100111100111 (0x79E7 MSB first)
– Send more than 50 SWCLKTCK cycles with SWDIOTMS = 1
– Send more than 50 SWCLKTCK cycles with SWDIOTMS = 1
– Send the 16-bit sequence on SWDIOTMS = 0011110011100111 (0x3CE7 MSB
– Send more than 50 SWCLKTCK cycles with SWDIOTMS = 1
first)
SWJ-DP Pin List
JTAG Port
TMS
TDO
TCK
TDI
TRACESWO (optional: trace)
Serial Wire Debug Port
SWCLK
SWDIO
SAM3X/A
SAM3X/A
-
219
219