-/* LIBFTDI EEPROM access example
+/* Libftdi example for asynchronous read/write.
This program is distributed under the GPL, version 2
*/
+/* This program switches to MPSSE mode, and sets and then reads back
+ * the high byte 3 times with three different values.
+ * The expected read values are hard coded in ftdi_init
+ * with 0x00, 0x55 and 0xaa
+ *
+ * Make sure that that nothing else drives some bit of the high byte
+ * or expect a collision for a very short time and some differences
+ * in the data read back.
+ *
+ * Result should be the same without any option or with either
+ * -r or -w or -b.
+ */
+
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
}
}
- // Select first interface
+ /* Select first free interface */
ftdi_set_interface(ftdi, INTERFACE_ANY);
struct ftdi_device_list *devlist;
goto do_deinit;
}
ftdi_list_free(&devlist);
- int err = ftdi_usb_purge_buffers(ftdi);
+ int err = ftdi_tcioflush(ftdi);
if (err != 0) {
- fprintf(stderr, "ftdi_usb_purge_buffer: %d: %s\n",
+ fprintf(stderr, "ftdi_tcioflush: %d: %s\n",
err, ftdi_get_error_string(ftdi));
retval = -1;
goto do_deinit;
err, ftdi_get_error_string(ftdi));
return -1;
}
- uint8_t ftdi_init[15] = {TCK_DIVISOR, 0x00, 0x00,
+#define DATA_TO_READ 3
+ uint8_t ftdi_init[] = {TCK_DIVISOR, 0x00, 0x00,
+ /* Set High byte to zero.*/
SET_BITS_HIGH, 0, 0xff,
GET_BITS_HIGH,
+ /* Set High byte to 0x55.*/
SET_BITS_HIGH, 0x55, 0xff,
GET_BITS_HIGH,
+ /* Set High byte to 0xaa.*/
SET_BITS_HIGH, 0xaa, 0xff,
- GET_BITS_HIGH};
+ GET_BITS_HIGH,
+ /* Set back to high impedance.*/
+ SET_BITS_HIGH, 0x00, 0x00 };
struct ftdi_transfer_control *tc_read;
struct ftdi_transfer_control *tc_write;
uint8_t data[3];
if (do_read) {
- tc_read = ftdi_read_data_submit(ftdi, data, 3);
+ tc_read = ftdi_read_data_submit(ftdi, data, DATA_TO_READ);
}
if (do_write) {
- tc_write = ftdi_write_data_submit(ftdi, ftdi_init, 15);
+ tc_write = ftdi_write_data_submit(ftdi, ftdi_init, sizeof(ftdi_init));
int transfer = ftdi_transfer_data_done(tc_write);
- printf("Async write %d\n", transfer);
+ if (transfer != sizeof(ftdi_init)) {
+ printf("Async write failed : %d\n", transfer);
+ }
} else {
- int written = ftdi_write_data(ftdi, ftdi_init, 15);
- if (written != 15) {
- printf("Sync write failed\n");
+ int written = ftdi_write_data(ftdi, ftdi_init, sizeof(ftdi_init));
+ if (written != sizeof(ftdi_init)) {
+ printf("Sync write failed: %d\n", written);
}
}
if (do_read) {
int transfer = ftdi_transfer_data_done(tc_read);
- printf("Async Read %d\n", transfer);
+ if (transfer != DATA_TO_READ) {
+ printf("Async Read failed:%d\n", transfer);
+ }
} else {
int index = 0;
- while (index < 3) {
+ ftdi->usb_read_timeout = 1;
+ int i = 1000; /* Fail if read did not succeed in 1 second.*/
+ while (i--) {
int res = ftdi_read_data(ftdi, data + index, 3 - index);
if (res < 0) {
printf("Async read failure at %d\n", index);
} else {
index += res;
}
+ if (res == 3) {
+ break;
+ }
+ }
+ if (i < 1) {
+ printf("Async read unsuccessful\n");
}
}
printf("Read %02x %02x %02x\n", data[0], data[1], data[2]);