3 Example to use CBUS bitbang mode of newer chipsets.
4 You must enable CBUS bitbang mode in the EEPROM first.
6 Thanks to Steve Brown <sbrown@ewol.com> for the
7 the information how to do it.
9 The top nibble controls input/output and the bottom nibble
10 controls the state of the lines set to output. The datasheet isn't clear
11 what happens if you set a bit in the output register when that line is
12 conditioned for input. This is described in more detail
13 in the FT232R bitbang app note.
19 | |------ Output Control 0->LO, 1->HI
20 |----------- Input/Output 0->Input, 1->Output
23 All pins to output with 0 bit high: 0xF1 (11110001)
24 Bits 0 and 1 to input, 2 and 3 to output and masked high: 0xCC (11001100)
26 This program is distributed under the GPL, version 2
33 int main(int argc, char **argv)
35 struct ftdi_context ftdic;
38 unsigned char bitmask;
42 f = ftdi_usb_open(&ftdic, 0x0403, 0x6001);
43 if(f < 0 && f != -5) {
44 fprintf(stderr, "unable to open ftdi device: %d (%s)\n", f, ftdi_get_error_string(&ftdic));
47 printf("ftdi open succeeded: %d\n",f);
51 printf("enabling CBUS mode\n");
52 f = ftdi_set_bitmode(&ftdic, bitmask, 0x20); // cbus[0] as input (high), cbus[1-3] as output
54 fprintf(stderr, "set_bitmode failed for 0x%x, error %d (%s)\n", bitmask, f, ftdi_get_error_string(&ftdic));
60 f = ftdi_write_data(&ftdic, buf, 1);
62 fprintf(stderr,"write failed for 0x%x, error %d (%s)\n", buf[0], f, ftdi_get_error_string(&ftdic));
67 f = ftdi_read_pins(&ftdic, &buf[0]);
69 fprintf(stderr, "read_pins failed, error %d (%s)\n", f, ftdi_get_error_string(&ftdic));
73 printf("disabling bitbang mode\n");
74 ftdi_disable_bitbang(&ftdic);
76 ftdi_usb_close(&ftdic);