Wim Huiskamp / SWO

Serial Wire Output (SWO) viewer for tracing purposes. Tested on F401 and ST-LINK Utility as well as for F103 and Segger J-Link SWO viewer.

Dependents:   WiFi_Scanner mbed_nucleo_swo DISCO-F429ZI_LCDTS_demo_richard TEST_SM_SPEED

SWO.cpp@0:0fd55660fc26, 2014-03-28 (annotated)

Committer:
wim
Date:
Fri Mar 28 19:32:13 2014 +0000
Revision:
0:0fd55660fc26
Child:
1:bae4cff278f6
First Test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wim 0:0fd55660fc26 1
wim 0:0fd55660fc26 2 #include "SWO.h"
wim 0:0fd55660fc26 3
wim 0:0fd55660fc26 4
wim 0:0fd55660fc26 5 /*********************************************************************
wim 0:0fd55660fc26 6 *
wim 0:0fd55660fc26 7 * Defines for Cortex-M debug unit
wim 0:0fd55660fc26 8 */
wim 0:0fd55660fc26 9 #define ITM_STIM_U32(n) (*(volatile unsigned int*)(0xE0000000+4*n)) // Stimulus Port n Register word access
wim 0:0fd55660fc26 10 //#define ITM_STIM_U32_0 (*(volatile unsigned int*)0xE0000000) // Stimulus Port 0 Register word access
wim 0:0fd55660fc26 11 //#define ITM_STIM_U8_0 (*(volatile char*)0xE0000000) // Stimulus Port 0 Register byte access
wim 0:0fd55660fc26 12 #define ITM_ENA (*(volatile unsigned int*)0xE0000E00) // Trace Enable Ports Register
wim 0:0fd55660fc26 13 #define ITM_TCR (*(volatile unsigned int*)0xE0000E80) // Trace control register
wim 0:0fd55660fc26 14
wim 0:0fd55660fc26 15
wim 0:0fd55660fc26 16
wim 0:0fd55660fc26 17 /*********************************************************************
wim 0:0fd55660fc26 18 *
wim 0:0fd55660fc26 19 * SWO_PrintChar()
wim 0:0fd55660fc26 20 *
wim 0:0fd55660fc26 21 * @brief
wim 0:0fd55660fc26 22 * Checks if SWO is set up. If it is not, return,
wim 0:0fd55660fc26 23 * to avoid program hangs if no debugger is connected.
wim 0:0fd55660fc26 24 * If it is set up, print a character to the ITM_STIM register
wim 0:0fd55660fc26 25 * in order to provide data for SWO.
wim 0:0fd55660fc26 26 * @param c The Character to be printed.
wim 0:0fd55660fc26 27 * @notes Additional checks for device specific registers can be added.
wim 0:0fd55660fc26 28 */
wim 0:0fd55660fc26 29 void SWO_PrintChar(char c) {
wim 0:0fd55660fc26 30 //
wim 0:0fd55660fc26 31 // Check if ITM_TCR.ITMENA is set
wim 0:0fd55660fc26 32 //
wim 0:0fd55660fc26 33 if ((ITM_TCR & 1) == 0) {
wim 0:0fd55660fc26 34 return;
wim 0:0fd55660fc26 35 }
wim 0:0fd55660fc26 36 //
wim 0:0fd55660fc26 37 // Check if stimulus port is enabled
wim 0:0fd55660fc26 38 //
wim 0:0fd55660fc26 39 if ((ITM_ENA & 1) == 0) {
wim 0:0fd55660fc26 40 return;
wim 0:0fd55660fc26 41 }
wim 0:0fd55660fc26 42 //
wim 0:0fd55660fc26 43 // Wait until STIMx is ready,
wim 0:0fd55660fc26 44 // then send data
wim 0:0fd55660fc26 45 //
wim 0:0fd55660fc26 46 // while ((ITM_STIM_U8(0) & 1) == 0);
wim 0:0fd55660fc26 47 // ITM_STIM_U8(0) = c;
wim 0:0fd55660fc26 48
wim 0:0fd55660fc26 49 while ((ITM_STIM_U32(0) & 1) == 0);
wim 0:0fd55660fc26 50 ITM_STIM_U32(0) = c;
wim 0:0fd55660fc26 51 }
wim 0:0fd55660fc26 52
wim 0:0fd55660fc26 53 /*********************************************************************
wim 0:0fd55660fc26 54 *
wim 0:0fd55660fc26 55 * SWO_PrintString()
wim 0:0fd55660fc26 56 *
wim 0:0fd55660fc26 57 * @brief Print a string via SWO.
wim 0:0fd55660fc26 58 * @param *s The string to be printed.
wim 0:0fd55660fc26 59 *
wim 0:0fd55660fc26 60 */
wim 0:0fd55660fc26 61 void SWO_PrintString(const char *s) {
wim 0:0fd55660fc26 62 //
wim 0:0fd55660fc26 63 // Print out character per character
wim 0:0fd55660fc26 64 //
wim 0:0fd55660fc26 65 while (*s) {
wim 0:0fd55660fc26 66 SWO_PrintChar(*s++);
wim 0:0fd55660fc26 67 }
wim 0:0fd55660fc26 68 }