/** 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 PDI interface on the target and enables access to the internal NVM controller. * * \return Boolean true if the PDI interface was enabled successfully, false otherwise */ bool XMEGANVM_EnablePDI(void) { /* 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 32 USART bits */ XPROGTarget_SendByte(PDI_CMD_STCS | PDI_CTRL_REG); XPROGTarget_SendByte(0x02); /* 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 */ return XMEGANVM_WaitWhileNVMBusBusy(); }