/**********************************************************
* Performs AAP Window Expansion. This function will reset
* target, send the AAP expansion sequence, initialize the
* debug interface and verify that AAP can be accessed.
* It will try several delays between reset is released
* and reading the AAP in case the reset line has a slow
* ramp-up.
*
* After this function completes the AAP registers are
* available. If it fails to access the AAP, it will
* throw an exception.
*
**********************************************************/
void performAapExpansion(void)
{
uint32_t dpId, apId;
int i,j;
bool success = false;
for ( i=0; i<AAP_EXPANSION_RETRY_COUNT; i++ ) {
/* Pull reset pin low */
GPIO_PinOutClear((GPIO_Port_TypeDef)RESET_PORT, RESET_PIN);
SWCLK_CLR();
delayMs(50);
/* Send the AAP Window expansion sequence */
aapExtensionSequence();
/* Release reset */
delayUs(10);
GPIO_PinOutSet((GPIO_Port_TypeDef)RESET_PORT, RESET_PIN);
/* Try different delays in case of slow reset ramp */
for ( j=0; j<i; j++ ) {
delayUs(10);
}
/* Connect to SW-DP */
TRY
dpId = initDp();
apId = readApId();
if ( verifyDpId(dpId) && apId == EFM32_AAP_ID )
{
/* Success! AAP registers can now be accessed.
* We cannot return in the middle of a TRY block.
* Set flag here and return after ENDTRY */
success = true;
}
CATCH
/* Do nothing in case of error. We retry. */
ENDTRY
/* Return if we found the AAP registers*/
if ( success )
{
printf("AAP registers found\n");
return;
}
}
/* Failed to get access to AAP registers. Raise an error. */
RAISE(SWD_ERROR_AAP_EXTENSION_FAILED);
}
/**********************************************************
* Performs the initialization sequence on the SW-DP.
* After this completes the debug interface can be used.
* Raises an exception on any error during connection.
**********************************************************/
void connectToTarget(void)
{
uint32_t dpId,apId;
delayUs(500);
printf("Connecting to target...\n");
dpId = initDp();
/* Verify that the DP returns the correct ID */
if ( !verifyDpId(dpId) )
{
printf("Read IDCODE = 0x%.8x\n", dpId);
RAISE(SWD_ERROR_INVALID_IDCODE);
}
/* Verify that the AP returns the correct ID */
int retry = AHB_IDR_RETRY_COUNT;
while ( retry > 0 )
{
apId = readApId();
if ( verifyAhbApId(apId) )
{
/* Success. AHB-AP registers found */
break;
}
retry--;
}
/* In case we did NOT find the AHB-AP registers check
* if the chip is locked or if some other error ocurred. */
if ( !verifyAhbApId(apId) )
{
/* If the ID is from AAP, the MCU is locked.
* Debug access is not available. */
if ( apId == EFM32_AAP_ID )
{
RAISE(SWD_ERROR_MCU_LOCKED);
}
else
{
/* The AP ID was not from AAP nor AHB-AP. This is an error. */
printf("Read IDR = 0x%.8x\n", apId);
RAISE(SWD_ERROR_INVALID_IDR);
}
}
/* Set up parameters for AHB-AP. This must be done before accessing
* internal memory. */
initAhbAp();
/*
* On Zero Gecko it is possible that the device is locked
* even though we reach this point. We have to see if
* we can access the AAP registers which are memory mapped
* on these devices. The function will raise an exception
* if the device is a Zero Gecko and is currently locked.
*/
if ( apId == EFM32_AHBAP_ID_2 )
{
checkIfZeroGeckoIsLocked();
}
haltTarget();
/* Get device name */
char deviceName[30];
getDeviceName(deviceName);
printf("Target is %s\n", deviceName);
/* Read the unique ID of the MCU */
uint64_t uniqueId = readUniqueId();
printf("Unique ID = 0x%.16llx\n", uniqueId);
}