first sorry if this is a simple question but I can't figure this out. I have this development board and on page 19 on the kits user guide the block diagram shows a RS232 line and on page 20 and 22 the schematic show the pins I need to connect to use RS232. My problem is that, despite being able to configure the fpga/cpld, I cannot find the com port on my computer (using pyserial and the following code(I tried changing COM%s in line 15 to FTUSB-%s)). So my questions are:
What interface does the FTDI, ft2232h USB to UART/FIFO, chip use (Serial, parallel... ) on the computer's end (like arduino's virtual COM port)?
On lattice's software there are 3 options to program the device. the program shows the following: HW-USBN-2b (FTDI) (with port as FTUSB-0), HW-USBN-2b (with port as ezUSB-0) and HW-DLN-3C. How can I use either of them to communicate with the device outside of Lattice's software?
thanks for you time.
1) RS232 is a combination of UART with certain voltage levels for the high and low (i.e. +3 to +15V and -3 to -15V afaik. Never ever connect a RS232 adapter to standard 3.3V or 5V devices e.g. UART, TTL-UART etc. The Lattice Semiconductor document just plainly missuses the term RS232 - try not to fall for it (IMHO the performance of their products strongly anticorrelates with the quality of their documentation and support).
2) page 19 of the linked doc shows the sections: Ordering Information, Technical Support Assistance, Revision History. Shifted by one page?
3) The FT2232H can be used in multiple modes. This depends on the way how it is addressed and of the settings flashed to the EEPROM connected to it (on the dev board is one placed but the FT2232H can be used without as well). The dev board is in the standard configuration designed to be programmed via the JTAG pins and the FT2232H is opened via the D2XX driver by lattice diamond. For that reason they flashed the EEPROM with settings which prohibits the use as virtual com port. The FTDI flash software can be used to change that behavior - for each bank seperately.
4) The solder bridges can be used to rearrange the connections (e.g. if one wants to change from the JTAG interface to the SPI or I2C programming interface). In your case you most likely want to place bridges on R14 and R15 to make the proper connection for an UART link to the port B of the FT2232H. EDIT: This way Port A can be used in JTAG mode to program the FT2232H and port B to communicate via e.g. UART or even other modes like the fast opto or the parallel bus/FIFO - if the correct bridges are soldered. Changing the EEPROM settings might be still required to make Port B visible as VCP if one want to avoid the usage of the D2XXX driver.