> 2.1 | Connecting the ME

> Depending on the selected interface, gWinSwup uses the following lines:

> Table 2: | Required lines

> Used ME interface | Lines used on ME side | Lines used on application side (e.g. PC)
> ASC0 / ASC1 | RXD0, TXD0, IGT, GND | RXD, TXD, DTR connected to IGT of ME, GND
> USB | IGT, USB_DP, USB_DN, VUSB_IN | Data, power supply, GND lines of USB

> Connecting the module

> • | The ME interface used for the download (ASC0, ASC1 or USB) shall connect to an appropriate port (COMx, USB) of the computer where the gWinSwup software is located.

> Furthermore, when downloading firmware over ASC0 or ASC1 it is recommended to have a connection between the ME’s IGT line and the computer’s DTR line. This enables gWinSwup to start the ME in the following cases: a) at the beginning of the download if the ME is still in Power Down mode, b) after successful firmware transfer, to restore the original baudrate of the ME if the selected gWinSwup baudrate was not identical with the ME’s original baudrate (AT+IPR). If a) and b) are not necessary, because the ME is switched on before gWinSwup starts and because the baud rates selected with gWinSwup and AT+IPR are the same, there is no need to toggle IGT during the download process, and thus no need to connect both lines.
> On the DSB75 Support Board, the connection between IGT and DTR is implemented for the first serial interface. So, the DSB75 is well suited for downloading the firmware over the ME’s ASC0 interface. All you need to do is to plug the serial cable and the power supply (9-15 Volts) for powering the DSB75 and the connected ME. Another solution is building a specialized download cable as suggested in Section 4.1. Design recommendations for connecting DTR and IGT can be found in the schematic example of a download cable shown in Figure 10. For the USB interface, the connection between DTR and IGT is not relevant, but the ME must always be switched on before starting the download.
> Connecting the TC65 Terminal

> • | For the TC65 Terminal no extra hardware is required as its serial port (ASC0 only) can be easily plugged to a free COM port of the computer which holds gWinSwup software.