Table 193. Flexible Trace Pin Assignment - STMicroelectronics RM0365 Reference Manual

RM0365
TPUI TRACE pin assignment
By default, these pins are NOT assigned. They can be assigned by setting the
TRACE_IOEN and TRACE_MODE bits in the MCU Debug component configuration
register. This configuration has to be done by the debugger host.
In addition, the number of pins to assign depends on the trace configuration (asynchronous
or synchronous).
•
Asynchronous mode: 1 extra pin is needed
• Synchronous mode (Available in STM32F302xx only): from 2 to 5 extra pins are
needed depending on the size of the data trace port register (1, 2 or 4) :
–
–
–
–
–
To assign the TRACE pin, the debugger host must program the bits TRACE_IOEN and
TRACE_MODE[1:0] of the Debug MCU configuration Register (DBGMCU_CR). By default
the TRACE pins are not assigned.
This register is mapped on the external PPB and is reset by the PORESET (and not by the
SYSTEM reset). It can be written by the debugger under SYSTEM reset.
DBGMCU_CR
register
TRACE
assigned for:
TRACE
_MODE
_IOEN
[1:0]
No Trace
0 XX
(default state)
Asynchronous
1 00
Synchronous
1 01
Trace 1 bit
Synchronous
1 10
Trace 2 bit
Synchronous
1 11
Trace 4 bit
1. When Serial Wire mode is used, it is released. But when JTAG is used, it is assigned to JTDO.
Note: By default, the TRACECLKIN input clock of the TPIU is tied to GND. It is assigned to HCLK
two clock cycles after the bit TRACE_IOEN has been set.
Synchronous trace port availability depends on the chosen package.
TRACECK
TRACED(0) if port size is configured to 1, 2 or 4
TRACED(1) if port size is configured to 2 or 4
TRACED(2) if port size is configured to 4
TRACED(3) if port size is configured to 4

Table 193. Flexible TRACE pin assignment

Pins
PB3 / JTDO/
TRACESWO
(1)
Released
TRACESWO
Trace
(1)
Released
DocID025202 Rev 7
TRACE IO pin assigned
PE2 / PE3 /
TRACECK TRACED[0]
- -
TRACECK TRACED[0]
TRACECK TRACED[0] TRACED[1]
TRACECK TRACED[0] TRACED[1] TRACED[2] TRACED[3]
Debug support (DBG)
PE4 / PE5 /
TRACED[1] TRACED[2]
-
Released
(usable as GPIO)
- -
-
PE6 /
TRACED[3]
-
-
1060/1080
1066