/** Handler for the XPROG ENTER_PROGMODE command to establish a connection with the attached device. */
static void XPROGProtocol_EnterXPROGMode(void)
{
Endpoint_ClearOUT();
Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPNUM);
Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
bool NVMBusEnabled = false;
if (XPROG_SelectedProtocol == XPRG_PROTOCOL_PDI)
{
/* Enable PDI programming mode with the attached target */
XPROGTarget_EnableTargetPDI();
/* Store the RESET key into the RESET PDI register to keep the XMEGA in reset */
XPROGTarget_SendByte(PDI_CMD_STCS | PDI_RESET_REG);
XPROGTarget_SendByte(PDI_RESET_KEY);
/* Lower direction change guard time to 0 USART bits */
XPROGTarget_SendByte(PDI_CMD_STCS | PDI_CTRL_REG);
XPROGTarget_SendByte(0x07);
/* Enable access to the XPROG NVM bus by sending the documented NVM access key to the device */
XPROGTarget_SendByte(PDI_CMD_KEY);
for (uint8_t i = sizeof(PDI_NVMENABLE_KEY); i > 0; i--)
XPROGTarget_SendByte(PDI_NVMENABLE_KEY[i - 1]);
/* Wait until the NVM bus becomes active */
NVMBusEnabled = XMEGANVM_WaitWhileNVMBusBusy();
}
else if (XPROG_SelectedProtocol == XPRG_PROTOCOL_TPI)
{
/* Enable TPI programming mode with the attached target */
XPROGTarget_EnableTargetTPI();
/* Lower direction change guard time to 0 USART bits */
XPROGTarget_SendByte(TPI_CMD_SSTCS | TPI_CTRL_REG);
XPROGTarget_SendByte(0x07);
/* Enable access to the XPROG NVM bus by sending the documented NVM access key to the device */
XPROGTarget_SendByte(TPI_CMD_SKEY);
for (uint8_t i = sizeof(TPI_NVMENABLE_KEY); i > 0; i--)
XPROGTarget_SendByte(TPI_NVMENABLE_KEY[i - 1]);
/* Wait until the NVM bus becomes active */
NVMBusEnabled = TINYNVM_WaitWhileNVMBusBusy();
}
Endpoint_Write_Byte(CMD_XPROG);
Endpoint_Write_Byte(XPRG_CMD_ENTER_PROGMODE);
Endpoint_Write_Byte(NVMBusEnabled ? XPRG_ERR_OK : XPRG_ERR_FAILED);
Endpoint_ClearIN();
}
/** Enables the physical TPI interface on the target and enables access to the internal NVM controller.
*
* \return Boolean true if the TPI interface was enabled successfully, false otherwise
*/
bool TINYNVM_EnableTPI(void)
{
/* Enable TPI programming mode with the attached target */
XPROGTarget_EnableTargetTPI();
/* Lower direction change guard time to 32 USART bits */
XPROGTarget_SendByte(TPI_CMD_SSTCS | TPI_CTRL_REG);
XPROGTarget_SendByte(0x02);
/* Enable access to the XPROG NVM bus by sending the documented NVM access key to the device */
XPROGTarget_SendByte(TPI_CMD_SKEY);
for (uint8_t i = sizeof(TPI_NVMENABLE_KEY); i > 0; i--)
XPROGTarget_SendByte(TPI_NVMENABLE_KEY[i - 1]);
/* Wait until the NVM bus becomes active */
return TINYNVM_WaitWhileNVMBusBusy();
}
