SAM3S8C Atmel Corporation, SAM3S8C Datasheet - Page 221

• Manufacturer Part Number: SAM3S8C
• Manufacturer: Atmel Corporation

11.5.6.2
11.5.6.3
11.5.7
11.5.7.1
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
IEEE
Asynchronous Mode
5.4.3. How to Configure the TPIU
JTAG Boundary-scan Register
®
1149.1 JTAG Boundary Scan
The TPIU is configured in asynchronous mode, trace data are output using the single TRAC-
ESWO pin. The TRACESWO signal is multiplexed with the TDO signal of the JTAG Debug Port.
As a consequence, asynchronous trace mode is only available when the Serial Wire Debug
mode is selected since TDO signal is used in JTAG debug mode.
Two encoding formats are available for the single pin output:
This example only concerns the asynchronous trace mode.
IEEE 1149.1 JTAG Boundary Scan allows pin-level access independent of the device packaging
technology.
IEEE 1149.1 JTAG Boundary Scan is enabled when TST is tied to low, while JTAGSEL is high
during power-up, and must be kept in this state during the whole boundary scan operation. The
SAMPLE, EXTEST and BYPASS functions are implemented. In SWD/JTAG debug mode, the
ARM processor responds with a non-JTAG chip ID that identifies the processor. This is not IEEE
1149.1 JTAG-compliant.
It is not possible to switch directly between JTAG Boundary Scan and SWJ Debug Port opera-
tions. A chip reset must be performed after JTAGSEL is changed.
A Boundary-scan Descriptor Language (BSDL) file is provided on
test.
The Boundary-scan Register (BSR) contains a number of bits which correspond to active pins
and associated control signals.
Each SAM3 input/output pin corresponds to a 3-bit register in the BSR. The OUTPUT bit con-
tains data that can be forced on the pad. The INPUT bit facilitates the observability of data
applied to the pad. The CONTROL bit selects the direction of the pad.
For more information, please refer to BDSL files available for the SAM3 Series.
• Manchester encoded stream. This is the reset value.
• NRZ_based UART byte structure
• Set the TRCENA bit to 1 into the Debug Exception and Monitor Register (0xE000EDFC) to
• Write 0x2 into the Selected Pin Protocol Register
• Write 0x100 into the Formatter and Flush Control Register
• Set the suitable clock prescaler value into the Async Clock Prescaler Register to scale the
enable the use of trace and debug blocks.
baud rate of the asynchronous output (this can be done automatically by the debugging tool).
– Select the Serial Wire Output – NRZ
Atmel’s web site
SAM3S8/SD8
SAM3S8/SD8
to set up the
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