Sw Debug Port Pins; Flexible Sw-Dp Pin Assignment; Internal Pull-Up & Pull-Down On Sw Pins; Id Codes And Locking Mechanism - STMicroelectronics STM32F05 series Reference Manual

Debug support (DBG)
29.3.1

SW debug port pins

Two pins are used as outputs for the SW-DP as alternate functions of general purpose I/Os.
These pins are available on all packages.

Table 107. SW debug port pins

SW-DP pin name
SWDIO
SWCLK
29.3.2

Flexible SW-DP pin assignment

After reset (SYSRESETn or PORESETn), the pins used for the SW-DP are assigned as
dedicated pins which are immediately usable by the debugger host.
However, the MCU offers the possibility of disabling all or part of the SW-DP port and can
then release the associated pins for general-purpose I/O (GPIO) usage. For more details on
how to disable SW-DP port pins, please refer to
function multiplexer and mapping on page
29.3.3 Internal pull-up & pull-down on SW pins
The microncontroller embeds internal pull-up & pull-down resistors on the SW input pins:
●
SWDAT: internal pull-up
●
SWCLK: internal pull-down
Once the SW I/O is released by the user software, the GPIO controller takes control of these
pins. The reset states of the GPIO control registers put the I/Os in the equivalent states:
●
SWDAT: input pull-up
●
SWCLK: input pull-down
Having embedded pull-up and pull-down resistors removes the need to add external
resistors.
29.4

ID codes and locking mechanism

There are several ID codes inside the MCU. ST strongly recommends the tool
manufacturers (Keil, IAR, Raisonance, ...) to lock their debugger using the MCU device ID
located at address 0x40015800.
Only the DEV_ID(15:0) should be used for identification by the debugger/programmer tools
(the revision ID must not be taken into account).
720/742
SW debug port
Type Debug assignment
IO Serial Wire Data Input/Output
I Serial Wire Clock
sectionSection 8.3.2: I/O pin alternate
121.
Doc ID 018940 Rev 1
RM0091
Pin
assignment
PA13
PA14