/** Removes access to the target's NVM controller and physically disables the target's physical PDI interface. */
void XMEGANVM_DisablePDI(void)
{
XMEGANVM_WaitWhileNVMBusBusy();
/* Clear the RESET key in the RESET PDI register to allow the XMEGA to run - must perform this until the
* change takes effect, as in some cases it takes multiple writes (silicon bug?).
*/
do
{
/* Clear reset register */
XPROGTarget_SendByte(PDI_CMD_STCS(PDI_REG_RESET));
XPROGTarget_SendByte(0x00);
/* Read back the reset register, check to see if it took effect */
XPROGTarget_SendByte(PDI_CMD_LDCS(PDI_REG_RESET));
} while ((XPROGTarget_ReceiveByte() != 0x00) && TimeoutTicksRemaining);
XPROGTarget_DisableTargetPDI();
}
/** Busy-waits while the NVM controller is busy performing a NVM operation, such as a FLASH page read or CRC
* calculation.
*
* \return Boolean \c true if the NVM controller became ready within the timeout period, \c false otherwise
*/
bool XMEGANVM_WaitWhileNVMBusBusy(void)
{
/* Poll the STATUS register to check to see if NVM access has been enabled */
for (;;)
{
/* Send the LDCS command to read the PDI STATUS register to see the NVM bus is active */
XPROGTarget_SendByte(PDI_CMD_LDCS(PDI_REG_STATUS));
uint8_t StatusRegister = XPROGTarget_ReceiveByte();
/* We might have timed out waiting for the status register read response, check here */
if (!(TimeoutTicksRemaining))
return false;
/* Check the status register read response to see if the NVM bus is enabled */
if (StatusRegister & PDI_STATUS_NVM)
return true;
}
}
