5.23 DBG Guide

This chapter describes the file composition and the 8 public functions of the DBG driver in the N32G41x standard peripheral library: reading the customer ID and the device ID, parsing the revision number and device information from DBG_ID, and configuring peripheral behaviour while the core is halted. This SDK provides no standalone example project for DBG. Read the SWD pin assignment and the DBG_ID and DBG_CTRL register definitions together with the “Debug support (DBG)” chapter of the user manual, and take the errata sheet as the authority on known chip issues.

5.23.1 Related files

Relative path	Purpose
`firmware/n32g41x_std_periph_driver/inc/n32g41x_dbg.h`	Defines the `DBG_*_STOP` debug-halt macros and declares 8 public functions in the three sections ID retrieval, device information and configuration
`firmware/n32g41x_std_periph_driver/src/n32g41x_dbg.c`	Implements those 8 functions: byte-wise reads of two ID areas, parsing of the revision number, device model and FLASH and SRAM sizes from `DBG->ID`, and read-modify-write of `DBG->CTRL`
`firmware/CMSIS/device/n32g41x.h`	Defines `UCID_BASE`, `UID_BASE`, `DBGMCU_ID_BASE` and the length macros, the `DBG` register structure pointer, the ID field masks and the `DBG_CTRL` bit definitions

5.23.2 API reference

The following 8 public functions are listed in the declaration order of n32g41x_dbg.h in 3 groups; each entry gives a summary and the original comment above the function in n32g41x_dbg.c.

ID retrieval

GetUCID, GetUID, GetDBGMCU_ID

Device information

DBG_GetRevNum, DBG_GetDevNum, DBG_GetFlashSize, DBG_GetSramSize

Configuration

DBG_ConfigPeriph

void GetUCID(uint8_t *UCIDbuf)Get the 128-bit unique customer ID UCID.

Source comment

name    GetUCID.
fun     Get the 128-bit unique customer ID UCID.
param   UCIDbuf : pointer to a buffer of at least UCID_LENGTH bytes.
return  none

Use note: The implementation reads UCID_LENGTH (16) bytes byte by byte starting from UCID_BASE (0x1FFFF4D0) into UCIDbuf; the caller must provide a buffer of at least 16 bytes.

void GetUID(uint8_t *UIDbuf)Get the 96-bit unique device ID UID.

Source comment

name    GetUID.
fun     Get the 96-bit unique device ID UID.
param   UIDbuf : pointer to a buffer of at least UID_LENGTH bytes.
return  none

Use note: The implementation reads UID_LENGTH (12) bytes byte by byte starting from UID_BASE (0x1FFFF500) into UIDbuf; the caller must provide a buffer of at least 12 bytes.

void GetDBGMCU_ID(uint8_t *DBGMCU_IDbuf)get the DBG_ID number.

Source comment

name    GetDBGMCU_ID.
fun     get the DBG_ID number.
param   DBGMCU_IDbuf : pointer to a buffer of at least DBGMCU_ID_LENGTH bytes.
return  none

Use note: The implementation first reads DBG->ID as a word and then splits it into DBGMCU_ID_LENGTH (4) bytes, least significant byte first, into DBGMCU_IDbuf.

uint32_t DBG_GetRevNum(void)get the revision number.

Source comment

name    DBG_GetRevNum.
fun     get the revision number.
param   none
return  8-bit revision number: REV_NUM_H[3:0] (bits 7:4) and
        REV_NUM_L[3:0] (bits 3:0). Read-only, fixed at production.

Use note: The implementation returns the low 8 bits of DBG->ID, that is, the 8-bit revision number formed by REV_NUM_H[3:0] in bits 7:4 and REV_NUM_L[3:0] in bits 3:0.

uint32_t DBG_GetDevNum(void)get the device identifier.

Source comment

name    DBG_GetDevNum.
fun     get the device identifier.
param   none
return  Device identifier

Use note: The implementation places DEV_NUM_L[3:0] from bits 23:20 of DBG->ID into bits 3:0 of the result and DEV_NUM_H and DEV_NUM_M from bits 15:8 into bits 11:4, forming a 12-bit device model.

uint32_t DBG_GetFlashSize(void)Get FLASH size of this chip.

Source comment

name    DBG_GetFlashSize.
fun     Get FLASH size of this chip.
param   none
return  FLASH size in bytes. The value is the DBG_ID.FLASH[19:16] field
        multiplied by 32 KB, so it is always a multiple of 32 KB.

Use note: The implementation returns the product of FLASH[3:0] in bits 19:16 of DBG->ID and 32 KB, in bytes.

uint32_t DBG_GetSramSize(void)Get SRAM size of this chip.

Source comment

name    DBG_GetSramSize.
fun     Get SRAM size of this chip.
param   none
return  SRAM size in bytes. The value is the DBG_ID.SRAM[31:28] field
        multiplied by 8 KB, so it is always a multiple of 8 KB.

Use note: The implementation returns the product of SRAM[3:0] in bits 31:28 of DBG->ID and 8 KB, in bytes.

void DBG_ConfigPeriph(uint32_t DBG_Periph, FunctionalState Cmd)Configures the specified peripheral run or stop when the MCU under Debug mode.

Source comment

name    DBG_ConfigPeriph.
fun     Configures the specified peripheral run or stop when the MCU under Debug mode.
param   DBG_Periph :
                - DBG_IWDG_STOP         \* IWDG stopped when Core is halted. *\
                - DBG_WWDG_STOP         \* WWDG stopped when Core is halted. *\
                - DBG_ATIM1_STOP        \* ATIM1 counter stopped when core is halted *\
                - DBG_GTIM1_STOP        \* GTIM1 counter stopped when core is halted *\
                - DBG_GTIM2_STOP        \* GTIM2 counter stopped when core is halted *\
                - DBG_GTIM3_STOP        \* GTIM3 counter stopped when core is halted *\
                - DBG_CAN_STOP          \* CAN stopped when core is halted *\
                - DBG_I2C1SMBUS_TIMEOUT \* I2C1 SMBUS timeout mode stopped when Core is halted *\
                - DBG_I2C2SMBUS_TIMEOUT \* I2C2 SMBUS timeout mode stopped when Core is halted *\
                - DBG_ATIM2_STOP        \* ATIM2 counter stopped when core is halted *\
                - DBG_GTIM4_STOP        \* GTIM4 counter stopped when core is halted *\
                - DBG_BTIM1_STOP        \* BTIM1 counter stopped when core is halted *\
                - DBG_BTIM2_STOP        \* BTIM2 counter stopped when core is halted *\
param   Cmd:
          - ENABLE
          - DISABLE
return  none

Use note: When Cmd is not DISABLE the implementation ORs DBG_Periph into DBG->CTRL, otherwise it clears those bits; several macros can be passed as one bitwise OR to configure several peripherals at once.

5.23.3 Demo descriptions

This SDK provides no standalone example project for DBG.

5.23.4 Notes and troubleshooting

Scenario	Check & action	Source
Peripherals keep running while the core is halted at a breakpoint	Where the timer counters, the WWDG/IWDG counters, CAN reception or the I2C SMBUS timeout must also stop during a debug halt, use `DBG_ConfigPeriph` to set the corresponding bit in `DBG_CTRL`; the POR default of `DBG_CTRL` is 0 and a system reset does not reset this register.	User manual
The debugger cannot connect	The N32G41x debug interface is SWD, with SWDIO on PA13 and SWCLK on PA14; after a program turns these two pins into ordinary IO the debugger cannot connect, so keep a branch that restores SWD, as in the IORemap example of the GPIO section.	User manual
How the DBG registers may be accessed	The `DBG` registers must be accessed as words (32 bits) and their base address is 0xE0042000; `DBG_ID` supports 32-bit access only and holds fixed, unmodifiable values, so use the word-reading `DBG_GetRevNum` and `DBG_GetDevNum` when a revision number or device model is needed.	User manual
Combining the device model fields	The device model in `DBG_ID` consists of 12 bits in `DEV_NUM_H[3:0]`, `DEV_NUM_M[3:0]` and `DEV_NUM_L[3:0]`, held in bits 15:12, bits 11:8 and bits 23:20; after reading them in the manual order they must be combined by the application.	User manual
Writing the reserved bits	Bits 27:24 of `DBG_ID` and bits 31:21 and bits 7:0 of `DBG_CTRL` are reserved and must keep their reset values.	User manual

The N32G412 and N32G415 series errata sheet V1.0.0 (2026.6.30) lists a single row for revision A chips with an empty errata link column, and gives no specific entries.