itm_output.cpp

00001 /* ===================================================================
00002 Copyright © 2016, AVNET Inc.  
00003 
00004 Licensed under the Apache License, Version 2.0 (the "License"); 
00005 you may not use this file except in compliance with the License.
00006 You may obtain a copy of the License at
00007 
00008    http://www.apache.org/licenses/LICENSE-2.0
00009 
00010 Unless required by applicable law or agreed to in writing, 
00011 software distributed under the License is distributed on an 
00012 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
00013 either express or implied. See the License for the specific 
00014 language governing permissions and limitations under the License.
00015 
00016 ======================================================================== */
00017 
00018 //Used for ULINK output only
00019 //
00020 
00021 /* ITM registers */
00022 #define ITM_PORT0_U8          (*((volatile unsigned int  *)0xE0000000))
00023 #define ITM_PORT0_U32         (*((volatile unsigned long *)0xE0000000))
00024 #define ITM_TER               (*((volatile unsigned long *)0xE0000E00))
00025 #define ITM_TCR               (*((volatile unsigned long *)0xE0000E80))
00026 
00027 #define ITM_TCR_ITMENA_Msk    (1UL << 0)
00028 
00029 /*!< Value identifying \ref ITM_RxBuffer is ready for next character. */
00030 #define ITM_RXBUFFER_EMPTY    0x5AA55AA5
00031 
00032 /*!< Variable to receive characters. */
00033 extern
00034 volatile int ITM_RxBuffer;
00035 volatile int ITM_RxBuffer = ITM_RXBUFFER_EMPTY;
00036 
00037 /** \brief  ITM Send Character
00038 
00039     The function transmits a character via the ITM channel 0, and
00040     \li Just returns when no debugger is connected that has booked the output.
00041     \li Is blocking when a debugger is connected, but the previous character
00042         sent has not been transmitted.
00043 
00044     \param [in]     ch  Character to transmit.
00045 
00046     \returns            Character to transmit.
00047  */
00048 int ITM_putc (int ch) {
00049   if ((ITM_TCR & ITM_TCR_ITMENA_Msk) && /* ITM enabled */
00050       (ITM_TER & (1UL << 0)        )) { /* ITM Port #0 enabled */
00051     while (ITM_PORT0_U32 == 0);
00052     ITM_PORT0_U8 = (int)ch;
00053   }
00054   return (ch);
00055 }
00056 
00057 /** \brief  ITM Receive Character
00058 
00059     The function inputs a character via the external variable \ref ITM_RxBuffer.
00060     This variable is monitored and altered by the debugger to provide input.
00061 
00062     \return             Received character.
00063     \return         -1  No character pending.
00064  */
00065 int ITM_getc (void) {
00066   int ch = -1;                      /* no character available */
00067 
00068   if (ITM_RxBuffer != ITM_RXBUFFER_EMPTY) {
00069     ch = ITM_RxBuffer;
00070     ITM_RxBuffer = ITM_RXBUFFER_EMPTY;  /* ready for next character */
00071   }
00072 
00073   return (ch);
00074 }
00075 
00076 /** \brief  ITM send string
00077 
00078     The function sends a null terminated string via the external variable \ref ITM_RxBuffer.
00079     This variable is monitored and altered by the debugger to provide input.
00080 
00081     \return             Received character.
00082     \return         -1  No character pending.
00083  */
00084 int ITM_puts (char * str) {
00085   int i=0;
00086 
00087   while(str[i])
00088     ITM_putc(str[i++]);
00089   return i;
00090 }
00091