}
/*
- * Configure the FPGA for bitbang mode.
- * This sequence is documented in section 2. of the ASIX Sigma programming
- * manual. This sequence is necessary to configure the FPGA in the Sigma
- * into Bitbang mode, in which it can be programmed with the firmware.
+ * See Xilinx UG332 for Spartan-3 FPGA configuration. The SIGMA device
+ * uses FTDI bitbang mode for netlist download in slave serial mode.
+ * (LATER: The OMEGA device's cable contains a more capable FTDI chip
+ * and uses MPSSE mode for bitbang. -- Can we also use FT232H in FT245
+ * compatible bitbang mode? For maximum code re-use and reduced libftdi
+ * dependency? See section 3.5.5 of FT232H: D0 clk, D1 data (out), D2
+ * data (in), D3 select, D4-7 GPIOL. See section 3.5.7 for MCU FIFO.)
+ *
+ * 750kbps rate (four times the speed of sigmalogan) works well for
+ * netlist download. All pins except INIT_B are output pins during
+ * configuration download.
+ *
+ * Some pins are inverted as a byproduct of level shifting circuitry.
+ * That's why high CCLK level (from the cable's point of view) is idle
+ * from the FPGA's perspective.
+ *
+ * The vendor's literature discusses a "suicide sequence" which ends
+ * regular FPGA execution and should be sent before entering bitbang
+ * mode and sending configuration data. Set D7 and toggle D2, D3, D4
+ * a few times.
+ */
+#define BB_PIN_CCLK (1 << 0) /* D0, CCLK */
+#define BB_PIN_PROG (1 << 1) /* D1, PROG */
+#define BB_PIN_D2 (1 << 2) /* D2, (part of) SUICIDE */
+#define BB_PIN_D3 (1 << 3) /* D3, (part of) SUICIDE */
+#define BB_PIN_D4 (1 << 4) /* D4, (part of) SUICIDE (unused?) */
+#define BB_PIN_INIT (1 << 5) /* D5, INIT, input pin */
+#define BB_PIN_DIN (1 << 6) /* D6, DIN */
+#define BB_PIN_D7 (1 << 7) /* D7, (part of) SUICIDE */
+
+#define BB_BITRATE (750 * 1000)
+#define BB_PINMASK (0xff & ~BB_PIN_INIT)
+
+/*
+ * Initiate slave serial mode for configuration download. Which is done
+ * by pulsing PROG_B and sensing INIT_B. Make sure CCLK is idle before
+ * initiating the configuration download. Run a "suicide sequence" first
+ * to terminate the regular FPGA operation before reconfiguration.
*/
static int sigma_fpga_init_bitbang(struct dev_context *devc)
{
uint8_t suicide[] = {
- 0x84, 0x84, 0x88, 0x84, 0x88, 0x84, 0x88, 0x84,
+ BB_PIN_D7 | BB_PIN_D2,
+ BB_PIN_D7 | BB_PIN_D2,
+ BB_PIN_D7 | BB_PIN_D3,
+ BB_PIN_D7 | BB_PIN_D2,
+ BB_PIN_D7 | BB_PIN_D3,
+ BB_PIN_D7 | BB_PIN_D2,
+ BB_PIN_D7 | BB_PIN_D3,
+ BB_PIN_D7 | BB_PIN_D2,
};
uint8_t init_array[] = {
- 0x01, 0x03, 0x03, 0x01, 0x01, 0x01, 0x01, 0x01,
- 0x01, 0x01,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK | BB_PIN_PROG,
+ BB_PIN_CCLK | BB_PIN_PROG,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
+ BB_PIN_CCLK,
};
- int i, ret, timeout = (10 * 1000);
+ int retries, ret;
uint8_t data;
/* Section 2. part 1), do the FPGA suicide. */
sigma_write(suicide, sizeof(suicide), devc);
sigma_write(suicide, sizeof(suicide), devc);
- /* Section 2. part 2), do pulse on D1. */
+ /* Section 2. part 2), pulse PROG. */
sigma_write(init_array, sizeof(init_array), devc);
ftdi_usb_purge_buffers(&devc->ftdic);
- /* Wait until the FPGA asserts D6/INIT_B. */
- for (i = 0; i < timeout; i++) {
+ /* Wait until the FPGA asserts INIT_B. */
+ retries = 10;
+ while (retries--) {
ret = sigma_read(&data, 1, devc);
if (ret < 0)
return ret;
- /* Test if pin D6 got asserted. */
- if (data & (1 << 5))
- return 0;
- /* The D6 was not asserted yet, wait a bit. */
+ if (data & BB_PIN_INIT)
+ return SR_OK;
g_usleep(10 * 1000);
}
*/
static int sigma_fpga_init_la(struct dev_context *devc)
{
- /* Initialize the logic analyzer mode. */
+ /*
+ * TODO Construct the sequence at runtime? Such that request data
+ * and response check values will match more apparently?
+ */
uint8_t mode_regval = WMR_SDRAMINIT;
uint8_t logic_mode_start[] = {
+ /* Read ID register. */
REG_ADDR_LOW | (READ_ID & 0xf),
REG_ADDR_HIGH | (READ_ID >> 4),
- REG_READ_ADDR, /* Read ID register. */
+ REG_READ_ADDR,
+ /* Write 0x55 to scratch register, read back. */
REG_ADDR_LOW | (WRITE_TEST & 0xf),
REG_DATA_LOW | 0x5,
REG_DATA_HIGH_WRITE | 0x5,
- REG_READ_ADDR, /* Read scratch register. */
+ REG_READ_ADDR,
+ /* Write 0xaa to scratch register, read back. */
REG_DATA_LOW | 0xa,
REG_DATA_HIGH_WRITE | 0xa,
- REG_READ_ADDR, /* Read scratch register. */
+ REG_READ_ADDR,
+ /* Initiate SDRAM initialization in mode register. */
REG_ADDR_LOW | (WRITE_MODE & 0xf),
REG_DATA_LOW | (mode_regval & 0xf),
REG_DATA_HIGH_WRITE | (mode_regval >> 4),
};
-
uint8_t result[3];
int ret;
- /* Initialize the logic analyzer mode. */
+ /*
+ * Send the command sequence which contains 3 READ requests.
+ * Expect to see the corresponding 3 response bytes.
+ */
sigma_write(logic_mode_start, sizeof(logic_mode_start), devc);
-
- /* Expect a 3 byte reply since we issued three READ requests. */
- ret = sigma_read(result, 3, devc);
- if (ret != 3)
+ ret = sigma_read(result, ARRAY_SIZE(result), devc);
+ if (ret != ARRAY_SIZE(result))
goto err;
-
if (result[0] != 0xa6 || result[1] != 0x55 || result[2] != 0xaa)
goto err;
return SR_OK;
+
err:
sr_err("Configuration failed. Invalid reply received.");
return SR_ERR;
static int sigma_fw_2_bitbang(struct sr_context *ctx, const char *name,
uint8_t **bb_cmd, gsize *bb_cmd_size)
{
- size_t i, file_size, bb_size;
- char *firmware;
- uint8_t *bb_stream, *bbs;
+ uint8_t *firmware;
+ size_t file_size;
+ uint8_t *p;
+ size_t l;
uint32_t imm;
- int bit, v;
- int ret = SR_OK;
+ size_t bb_size;
+ uint8_t *bb_stream, *bbs, byte, mask, v;
/* Retrieve the on-disk firmware file content. */
firmware = sr_resource_load(ctx, SR_RESOURCE_FIRMWARE, name,
&file_size, SIGMA_FIRMWARE_SIZE_LIMIT);
if (!firmware)
- return SR_ERR;
+ return SR_ERR_IO;
/* Unscramble the file content (XOR with "random" sequence). */
+ p = firmware;
+ l = file_size;
imm = 0x3f6df2ab;
- for (i = 0; i < file_size; i++) {
+ while (l--) {
imm = (imm + 0xa853753) % 177 + (imm * 0x8034052);
- firmware[i] ^= imm & 0xff;
+ *p++ ^= imm & 0xff;
}
/*
* the bitbang samples, and release the allocated memory.
*/
bb_size = file_size * 8 * 2;
- bb_stream = (uint8_t *)g_try_malloc(bb_size);
+ bb_stream = g_try_malloc(bb_size);
if (!bb_stream) {
sr_err("%s: Failed to allocate bitbang stream", __func__);
- ret = SR_ERR_MALLOC;
- goto exit;
+ g_free(firmware);
+ return SR_ERR_MALLOC;
}
bbs = bb_stream;
- for (i = 0; i < file_size; i++) {
- for (bit = 7; bit >= 0; bit--) {
- v = (firmware[i] & (1 << bit)) ? 0x40 : 0x00;
- *bbs++ = v | 0x01;
+ p = firmware;
+ l = file_size;
+ while (l--) {
+ byte = *p++;
+ mask = 0x80;
+ while (mask) {
+ v = (byte & mask) ? BB_PIN_DIN : 0;
+ mask >>= 1;
+ *bbs++ = v | BB_PIN_CCLK;
*bbs++ = v;
}
}
+ g_free(firmware);
/* The transformation completed successfully, return the result. */
*bb_cmd = bb_stream;
*bb_cmd_size = bb_size;
-exit:
- g_free(firmware);
- return ret;
+ return SR_OK;
}
static int upload_firmware(struct sr_context *ctx,
return SR_OK;
}
- ret = ftdi_set_bitmode(&devc->ftdic, 0xdf, BITMODE_BITBANG);
+ /* Set the cable to bitbang mode. */
+ ret = ftdi_set_bitmode(&devc->ftdic, BB_PINMASK, BITMODE_BITBANG);
if (ret < 0) {
sr_err("ftdi_set_bitmode failed: %s",
ftdi_get_error_string(&devc->ftdic));
return SR_ERR;
}
-
- /* Four times the speed of sigmalogan - Works well. */
- ret = ftdi_set_baudrate(&devc->ftdic, 750 * 1000);
+ ret = ftdi_set_baudrate(&devc->ftdic, BB_BITRATE);
if (ret < 0) {
sr_err("ftdi_set_baudrate failed: %s",
ftdi_get_error_string(&devc->ftdic));
return SR_ERR;
}
- /* Initialize the FPGA for firmware upload. */
+ /* Initiate FPGA configuration mode. */
ret = sigma_fpga_init_bitbang(devc);
if (ret)
return ret;
- /* Prepare firmware. */
+ /* Prepare wire format of the firmware image. */
ret = sigma_fw_2_bitbang(ctx, firmware, &buf, &buf_size);
if (ret != SR_OK) {
sr_err("An error occurred while reading the firmware: %s",
return ret;
}
- /* Upload firmware. */
+ /* Write the FPGA netlist to the cable. */
sr_info("Uploading firmware file '%s'.", firmware);
sigma_write(buf, buf_size, devc);
g_free(buf);
- ret = ftdi_set_bitmode(&devc->ftdic, 0x00, BITMODE_RESET);
+ /* Leave bitbang mode and discard pending input data. */
+ ret = ftdi_set_bitmode(&devc->ftdic, 0, BITMODE_RESET);
if (ret < 0) {
sr_err("ftdi_set_bitmode failed: %s",
ftdi_get_error_string(&devc->ftdic));
return SR_ERR;
}
-
ftdi_usb_purge_buffers(&devc->ftdic);
-
- /* Discard garbage. */
while (sigma_read(&pins, 1, devc) == 1)
;
if (ret != SR_OK)
return ret;
+ /* Keep track of successful firmware download completion. */
devc->cur_firmware = firmware_idx;
-
sr_info("Firmware uploaded.");
return SR_OK;
projects / libsigrok.git / commitdiff