/*********************************************************************** * SEGGER Microcontroller GmbH * * The Embedded Experts * ************************************************************************ * * * (c) SEGGER Microcontroller GmbH * * All rights reserved * * www.segger.com * * * ************************************************************************ * * ************************************************************************ * * * * * Licensing terms * * * * The use in source and binary forms, with or without modification, * * is permitted for internal use only. The redistribution to any * * third party is prohibited. * * * * * * 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 ----------------------------- File : Template_UartTIF.JLinkScript Purpose : This script shows how to use the JLINK_UART_XXX() functions to use UART as a target interface. */ /********************************************************************* * * Constants (similar to defines) * ********************************************************************** */ // // User-specified constants to be used by PCode // __constant U32 _UART_BAUDRATE_HZ = 9600; // Use a baudrate all J-Link models can handle. __constant U32 _PIN_OVERRIDE_TMS = 2; // TMS/SWDIO pin is used as UART communication pin __constant U32 _TIMEOUT_SEND_1_BYTE = 5; // @9600 Baud, 1 char takes 10 * 104us for transmission. Considering that we might be at the edge of a MSInterrupt, add some additional delay. However, add some more as it does not really hurt __constant U32 _TIMEOUT_RECEIVE_1_BYTE = 3; __constant U32 _MAX_NUM_PINS_OVERRIDE = 8; /********************************************************************* * * Static data * ********************************************************************** */ U32 _aPINMode[8]; // Keep in sync with _MAX_NUM_PINS_OVERRIDE U32 _aPINState[8]; // Keep in sync with _MAX_NUM_PINS_OVERRIDE /********************************************************************* * * Local functions * ********************************************************************** */ /********************************************************************* * * _UART_WriteBytes * * Function description * Writes bytes via UART to target and swallows echoed bytes. * * Return value * >= 0 O.K. * < 0 Error */ static int _UART_WriteBytes(const U8* pData, int NumBytes, int TimeoutMs) { U8 Data; int r; int t; int NumBytesRem; NumBytesRem = NumBytes; JLINK_UART_Write(pData, NumBytesRem); t = JLINK_GetTime(); // // J-Link firmware echoes everything we write, so make sure we swallow these bytes // do { r = JLINK_UART_Read(&Data, 1); if (r == 1) { NumBytesRem -= 1; if (NumBytesRem == 0) { // Everything has been sent r = 0; break; } } r = JLINK_GetTime() - t; if (r > TimeoutMs) { //JLINK_SYS_Report1("Timeout while writing bytes: ", NumBytes); r = -1; break; } } while (1); return r; } /********************************************************************* * * _UART_ReadCharTimeout * * Function description * Reads a character with timeout. * * Return value * >= 0 O.K., number of bytes read * < 0 Error */ static int _UART_ReadCharTimeout(U8* pData, int TimeoutMs) { int r; int t; t = JLINK_GetTime(); do { r = JLINK_UART_Read(pData, 1); if (r == 1) { break; } r = JLINK_GetTime() - t; if (r > TimeoutMs) { //JLINK_SYS_Report1("Timeout while reading char: ", r); r = 0; break; } } while (1); return r; } /********************************************************************* * * _CommandSequenceViaUART * * Function description * Sends a arbitrary command sequence via UART * * Return value * >= 0: O.K. * < 0: Error */ static int _CommandSequenceViaUART(void) { int i; int r; U8 ch0; U8 ch1; U8 ch2; while (JLINK_UART_Read(&ch0, 1) == 1); // Before PIN override is executed, a lot of zeros may be read into JLink's circular buffer. So clear the buffer ch0 = 0x00; // Trigger baudrate detection ch1 = 0x55; // Arbitrary Command i = 0; r = JLINK_UART_Read(&ch0, 1); do { // Sequence might need to be sent multiple times... _UART_WriteBytes(&ch0, 1, _TIMEOUT_SEND_1_BYTE); JLINK_Delay_us(2000); // Arbitrary delay (may be needed) _UART_WriteBytes(&ch1, 1, _TIMEOUT_SEND_1_BYTE); ch2 = 0; r = _UART_ReadCharTimeout(&ch2, _TIMEOUT_RECEIVE_1_BYTE); if (r > 0) { // Received response from target? break; } i += 1; } while(i < 5); // Try 5 times if (r != 1) { //JLINK_SYS_Report1("Device did not respond: ", r); return 0; // Device may unresponsive } if (ch2 != 0xAA) { //JLINK_SYS_Report1(" Incorrect answer received from device", ch2); return -1; } JLINK_Delay_us(50000); // Sleep return 0; } /********************************************************************* * * Global functions * ********************************************************************** */ /********************************************************************* * * InitTarget() * * Function description * If present, called right before performing generic connect sequence. * Usually used for targets which need a special connect sequence. * E.g.: TI devices with ICEPick TAP on them where core TAP needs to be enabled via specific ICEPick sequences first * * Return value * >= 0: O.K. * < 0: Error * * Notes * (1) Must not use high-level API functions like JLINK_MEM_ etc. * (2) For target interface JTAG, this device has to setup the JTAG chain + JTAG TAP Ids. * (3) __probe attribute specifies that this function is executed in the J-Link firmware rather than on the PC side, so changes to global variables may only be temporarily valid inside this function (not guaranteed to be valid later) */ __probe int InitTarget(void) { int i; int r; // // Configure half-duplex UART on TMS/SWDIO pin // i = 0; do { _aPINMode[i] = JLINK_PIN_OVERRIDE_MODE_RELEASE; // Do not override any pin by default i += 1; } while(i < _MAX_NUM_PINS_OVERRIDE); _aPINMode[_PIN_OVERRIDE_TMS] = JLINK_PIN_OVERRIDE_MODE_UART_RXTX; // Half-duplex UART means Tx and Rx are on the same pin r = JLINK_PIN_Override(&_aPINMode[0], &_aPINState[0]); if (r < 0) { return r; } // // Init UART interface and send sequence // JLINK_UART_Init(_UART_BAUDRATE_HZ); r = _CommandSequenceViaUART(); JLINK_UART_DeInit(); // // Restore pin configuration of J-Link // i = 0; do { _aPINMode[i] = JLINK_PIN_OVERRIDE_MODE_RELEASE; // Do not override any pin by default i += 1; } while(i < _MAX_NUM_PINS_OVERRIDE); JLINK_PIN_Override(&_aPINMode[0], &_aPINState[0]); return r; }