/*********************************************************************** * SEGGER Microcontroller GmbH * * The Embedded Experts * ************************************************************************ * * * (c) SEGGER Microcontroller GmbH * * All rights reserved * * www.segger.com * * * ************************************************************************ * * ************************************************************************ * * * * * Licensing terms * * * * This software may be distributed to your customers free of charge. * * This grant of redistribution does not entitle YOU or enduser to * * receive from SEGGER hard-copy documentation, technical support, * * phone assistance, or enhancements or updates to the Software unless * * a specific agreement clearly states otherwise. * * * * * * THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDER "AS IS" AND ANY * * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER BE * * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * * DAMAGE. * * * ************************************************************************ -------------------------- END-OF-HEADER ----------------------------- Purpose: Implementation of the generic Cortex-M with ARMv7-M and ARMv6-M architecture device reset (Reset strategy Type 2: ResetPin). Literature: [1] J-Link User Guide [2] https://wiki.segger.com/J-Link_Reset_Strategies#Type_2:_ResetPin */ /********************************************************************* * * Constants, fixed * ********************************************************************** */ // // Registers (ARM) // __constant U32 _DHCSR_ADDR = 0xE000EDF0; // Debug Halting Control and Status Register __constant U32 _DEMCR_ADDR = 0xE000EDFC; // Debug Exception and Monitor Control Register // // Bits & Shifts (ARM) // __constant U32 _DP_CTRL_STAT_BIT_STICKYERR = (1 << 5); __constant U32 _DHCSR_DBGKEY = (0xA05F << 16); __constant U32 _DHCSR_C_DEBUGEN = (1 << 0); __constant U32 _DHCSR_C_HALT = (1 << 1); __constant U32 _DEMCR_VC_CORERESET = (1 << 0); __constant U32 _DEMCR_TRCENA = (1 << 24); /********************************************************************* * * Constants, configurable * ********************************************************************** */ // // Timeouts // __constant U32 _DEF_RESET_PULSE_LEN = 50; __constant U32 _DEF_RESET_DELAY = 100; __constant U32 _DEF_BUSY_TIMEOUT = 500; // // AHB-AP related defines // __constant U32 _INDEX_AHB_AP_CORTEX_M7 = 0; // AHB-AP connected to Cortex-M7 core. __constant U32 _ACC_SIZE_WORD = 2; /********************************************************************* * * Static code * ********************************************************************** */ /********************************************************************* * * _DAPClrStickyErr * * Function description * Clears the DAP sticky error flags. */ static void _DAPClrStickyErr(void) { U32 v; // // The DP is slightly different for JTAG and SWD regarding clearing sticky error bits. // if (JLINK_ActiveTIF == JLINK_TIF_SWD) { JLINK_CORESIGHT_WriteDP(JLINK_CORESIGHT_DP_REG_ABORT, 0x1E); } else { v = JLINK_CORESIGHT_ReadDP(JLINK_CORESIGHT_DP_REG_CTRL_STAT); v |= _DP_CTRL_STAT_BIT_STICKYERR; JLINK_CORESIGHT_WriteDP(JLINK_CORESIGHT_DP_REG_CTRL_STAT, v); } } /********************************************************************* * * _ConfigAP() * * Function description * Configures selected AP for debugging. */ static int _ConfigAP(U32 Index, U32 AccSize, U8 IsAHBnAPB) { U32 v; int r; // // Select AP and bank to use // v = 0 | (0 << 4) // Select bank 0 (this is default for most casese). | (Index << 24) // Select AP[Index] (AHB-AP) ; JLINK_CORESIGHT_WriteDP(JLINK_CORESIGHT_DP_REG_SELECT, v); // // Initialize DAP for debug use. // v = (AccSize << 0) // Set access size | (0 << 4) // No auto increment ; if (IsAHBnAPB) { v = v | (1 << 24) // Reserved | (1 << 25) // Private access | (1 << 29) // MasterType == Debug ; } else { v = v | (1 << 31) // DbgSwEnable == Enable ; } r = JLINK_CORESIGHT_WriteAP(JLINK_CORESIGHT_AP_REG_CTRL, v); if (r < 0) { JLINK_SYS_Report("Error: Failed to configure AP."); return -1; } return 0; } /********************************************************************* * * _InitDAP() * * Function description * Initializes DAP, so JLINK_CORESIGHT_ functions can be used. * * Return value * = 0 O.K. * < 0 Error */ static int _InitDAP(void) { U32 v; int r; int t; _DAPClrStickyErr(); // Clear sticky error flags and power up DAP // // Wait for power up DAP complete // r = -1; t = JLINK_GetTime() + _DEF_BUSY_TIMEOUT; do { r = JLINK_CORESIGHT_ReadDP(JLINK_CORESIGHT_DP_REG_CTRL_STAT); if (r == -1) { // Any error occurred while reading from the DP, we are done break; } v = r; if (v & (0xF << 28)) { // CSYSPWRUPACK and CDBGPWRUPACK set, so both ports have been completely powered? r = 0; break; } if ((t - JLINK_GetTime()) <= 0) { break; } } while(1); if (r < 0) { JLINK_SYS_Report("Error: Failed to initialize DAP."); return -1; } r = _ConfigAP(_INDEX_AHB_AP_CORTEX_M7, _ACC_SIZE_WORD, 1); // Finally configure the AP so we can use it. if (r < 0) { return -1; } JLINK_SYS_Report("DAP initialized successfully."); return 0; } /********************************************************************* * * Global functions * ********************************************************************** */ /********************************************************************* * * ResetTarget() * * Function description * Replaces reset strategies of DLL. No matter what reset type is selected in the DLL, if this function is present, it will be called instead of the DLL internal reset. * * Return value * <= 0 O.K. * < 0 Error * * Notes * (1) DLL expects target CPU to be halted / in debug mode, when leaving this function * (2) May use MEM_ API functions * (3) The caller ensures that the J-Link SW / FW caches are invalidated after this function */ int ResetTarget(void) { int t; int r; // // Halt the CPU // JLINK_SYS_Report("Reset: Halt core after reset via DEMCR.VC_CORERESET."); JLINK_MEM_WriteU32(_DHCSR_ADDR, (_DHCSR_DBGKEY | _DHCSR_C_HALT | _DHCSR_C_DEBUGEN)); // Halt the CPU JLINK_MEM_WriteU32(_DEMCR_ADDR, (_DEMCR_VC_CORERESET | _DEMCR_TRCENA)); // Set vector catch on reset (to halt the CPU immediately after reset) // // Issue reset request via nRESET pin // JLINK_SYS_Report("Reset: Reset device via reset pin."); JLINK_TIF_ActivateTargetReset(); JLINK_SYS_Sleep(_DEF_RESET_PULSE_LEN); JLINK_TIF_ReleaseTargetReset(); // // Give target some time to "recover" from RESET. This is because RESET typically has a capacitor connected and needs some // time to be deactivated. If the reset strategy worked, this is no problem since the CPU is already halted. // This delay here increases the stability. // JLINK_SYS_Sleep(_DEF_RESET_DELAY); // // Make sure DLL no longer assumes that device is halted and any cached CPU register values are valid. // JLINK_ExecCommand("InvalidateCPUState"); // // Manually halt CPU, in case vector catch did not work. // Can happen on devices which also reset the debug logic when toggling the reset pin. (E.g. Atmel SAM3U) // if (JLINK_TARGET_IsHalted() == 0) { JLINK_SYS_Report("Reset: VC_CORERESET did not halt CPU. (Debug logic also reset by reset pin?)."); JLINK_SYS_Report("Reset: Reconnecting and manually halting CPU."); r = _InitDAP(); // Reconnect after system reset. JLINK_TARGET_Halt(); // // Wait until CPU is halted. // t = JLINK_GetTime() + _DEF_BUSY_TIMEOUT; do { if (JLINK_TARGET_IsHalted()) { break; } if ((t - JLINK_GetTime()) < 0) { JLINK_SYS_Report("Reset: Timeout while waiting for CPU to halt."); r = -1; } } while (1); } // // Make sure we clear the vector catch we have set before // JLINK_MEM_WriteU32(_DEMCR_ADDR, (_DEMCR_TRCENA)); return r; } /*************************** end of file ****************************/