ConfigTargetSettings()

Called before InitTarget(). Mainly used to set some global DLL variables to customize the normal connect procedure. For ARM CoreSight devices this may be specifying the base address of some CoreSight components (ETM, CTI, ...) that cannot be auto-detected by J-Link due to erroneous ROM tables etc. May also be used to specify the device name in case debugger does not pass it to the DLL.

Prototype

int ConfigTargetSettings(void);

Notes and Limitations

May not, under absolutely NO circumstances, call any API functions that perform target communication.

• Should only set some global DLL variables

Use cases

Defining the JTAG chain

Example code

int ConfigTargetSettings(void) {
  JLINK_JTAG_DRPre  = 0;
  JLINK_JTAG_DRPost = 0;
  JLINK_JTAG_IRPre  = 0;
  JLINK_JTAG_IRPost = 0;
  JLINK_JTAG_IRLen  = 4;
  JLINK_JTAG_SetDeviceId(0, 0x1BB6402F);
  return 0;
}

Defining the AP map

Example code

int ConfigTargetSettings(void) { 
  JLINK_CORESIGHT_AddAP(0, CORESIGHT_AHB_AP);  // AP0
  JLINK_CORESIGHT_AddAP(1, CORESIGHT_AHB_AP);  // AP1
  JLINK_CORESIGHT_AddAP(2, CORESIGHT_APB_AP);  // AP2
  return 0;
}

Selecting a specific AP

Example code

int ConfigTargetSettings(void) { 
  JLINK_CORESIGHT_IndexAHBAPToUse = 0; // Select AP0 as AHB-AP
  JLINK_CORESIGHT_IndexAPBAPToUse = 2; // Select AP2 as APB-AP
  return 0;
}

Exclude illegal regions

The map region command can be used to exclude certain memory region(s). The J-Link DLL will ignore all read / write accesses to the specified region(s). This can be used if an IDE for example accesses an illegal memory address for some reason.

Example code

int ConfigTargetSettings(void) {
  JLINK_ExecCommand("map region 0xC0000000-0xC000FFFF X");
  return 0;
}

Initialize work RAM on connect

ECC RAM needs to be initialized to be used by the J-Link as work RAM. This code makes sure that the RAM is initialized on Connect.

Example code

int ConfigTargetSettings(void) {
  JLINK_ExecCommand("SetInitWorkRAMOnConnect = 1");
  return 0;
}