Hi, I have a question about the usage of the ftdi_set_bitmode function. I am using a development board from FTDI called MorphIC-II to evaluate the usage of the FT2232HQ chip. This board uses the A port as an IO port to communicate with a Cyclone FPGA, and the B-Port is connected to the programming pins of the FPGA as follows: BD[0] = DCLK BD[1] = DATA0 BD[2] = NCONFIG BD[3] = NSTATUS BD[4] = CONF_DONE BD[7] = DEV_RST
I am trying to use BITBANG mode to port B to set the DEV_RST line to 0, while leaving the other pins alone (by setting them as inputs). I have been able to do this with the libftd2xx library as follows: -----------ftd2xx code--------------------- ftStatus = FT_Open(1, &fthandle1); UCHAR Mask = 0x80; // only bit 7 is output UCHAR Mode = 1; // Set bit-bang mode ftStatus = FT_SetBitMode(fthandle1, Mask, Mode); UCHAR Value = 0x0; //set all bits to 0 ftStatus = FT_Write(fthandle1, &Value, 1, &BytesWritten); ------------end ftd2xx code ------------------- I am now trying to do the same thing with the libftdi library as follows: ----------libftdi code --------------------------- ftdi_init(&ftdic2) ftdi_set_interface(&ftdic2, INTERFACE_B); ftdi_usb_open(&ftdic2, 0x0403, 0x6010)); ftdi_set_bitmode(&ftdic2, 0x80, BITMODE_BITBANG); buf[0] = 0x0; ftdi_write_data(&ftdic2, buf, 1); -------- end libftdi code------------------------ But as soon as the ftdi_set_bitmode function is called, the FPGA seems to reconfigure, as if one of the other pins (other than pin7) gets toggled. Am I misunderstanding how to use the bitmask in this call? Or is there some other problem that prevents me from using this library with this chip? Regards, Jo -- Dr Joachim Schambach tel: x1 512 471 1303 The University of Texas at Austin fax: x1 814 295 5111 Department of Physics email: [email protected] 1 University Station C1600 Austin, Texas 78712-0264, USA -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
