2 * This file is part of the libsigrok project.
4 * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 /* The VCD input module has the following options:
22 * numchannels: Maximum number of channels to use. The channels are
23 * detected in the same order as they are listed
24 * in the $var sections of the VCD file.
26 * skip: Allows skipping until given timestamp in the file.
27 * This can speed up analyzing of long captures.
29 * Value < 0: Skip until first timestamp listed in
32 * Value = 0: Do not skip, instead generate samples
33 * beginning from timestamp 0.
35 * Value > 0: Start at the given timestamp.
37 * downsample: Divide the samplerate by the given factor.
38 * This can speed up analyzing of long captures.
40 * compress: Compress idle periods longer than this value.
41 * This can speed up analyzing of long captures.
42 * Default 0 = don't compress.
44 * Based on Verilog standard IEEE Std 1364-2001 Version C
47 * - $var with 'wire' and 'reg' types of scalar variables
48 * - $timescale definition for samplerate
49 * - multiple character variable identifiers
51 * Most important unsupported features:
52 * - vector variables (bit vectors etc.)
53 * - analog, integer and real number variables
54 * - $dumpvars initial value declaration
56 * - more than 64 channels
63 #include "libsigrok.h"
64 #include "libsigrok-internal.h"
66 #define LOG_PREFIX "input/vcd"
68 #define DEFAULT_NUM_CHANNELS 8
69 #define CHUNKSIZE 1024
87 /* Read until specific type of character occurs in file.
88 * Skip input if dest is NULL.
90 * 'W' read until whitespace
91 * 'N' read until non-whitespace, and ungetc() the character
94 static gboolean read_until(FILE *file, GString *dest, char mode)
104 sr_err("Unexpected EOF.");
108 if (mode == 'W' && g_ascii_isspace(c))
111 if (mode == 'N' && !g_ascii_isspace(c)) {
117 prev[0] = prev[1]; prev[1] = prev[2]; prev[2] = prev[3]; prev[3] = c;
118 if (prev[0] == '$' && prev[1] == 'e' && prev[2] == 'n' && prev[3] == 'd') {
120 g_string_truncate(dest, dest->len - 3);
127 g_string_append_c(dest, c);
132 * Reads a single VCD section from input file and parses it to structure.
133 * e.g. $timescale 1ps $end => "timescale" "1ps"
135 static gboolean parse_section(FILE *file, gchar **name, gchar **contents)
138 GString *sname, *scontents;
140 /* Skip any initial white-space */
141 if (!read_until(file, NULL, 'N')) return FALSE;
143 /* Section tag should start with $. */
144 if (fgetc(file) != '$')
147 /* Read the section tag */
148 sname = g_string_sized_new(32);
149 status = read_until(file, sname, 'W');
151 /* Skip whitespace before content */
152 status = status && read_until(file, NULL, 'N');
154 /* Read the content */
155 scontents = g_string_sized_new(128);
156 status = status && read_until(file, scontents, '$');
157 g_strchomp(scontents->str);
159 /* Release strings if status is FALSE, return them if status is TRUE */
160 *name = g_string_free(sname, !status);
161 *contents = g_string_free(scontents, !status);
165 static void free_channel(void *data)
167 struct vcd_channel *vcd_ch = data;
168 g_free(vcd_ch->name);
169 g_free(vcd_ch->identifier);
173 static void release_context(struct context *ctx)
175 g_slist_free_full(ctx->channels, free_channel);
179 /* Remove empty parts from an array returned by g_strsplit. */
180 static void remove_empty_parts(gchar **parts)
183 gchar **dest = parts;
184 while (*src != NULL) {
194 * Parse VCD header to get values for context structure.
195 * The context structure should be zeroed before calling this.
197 static gboolean parse_header(FILE *file, struct context *ctx)
200 gchar *name = NULL, *contents = NULL;
201 gboolean status = FALSE;
202 struct vcd_channel *vcd_ch;
204 while (parse_section(file, &name, &contents)) {
205 sr_dbg("Section '%s', contents '%s'.", name, contents);
207 if (g_strcmp0(name, "enddefinitions") == 0) {
210 } else if (g_strcmp0(name, "timescale") == 0) {
212 * The standard allows for values 1, 10 or 100
213 * and units s, ms, us, ns, ps and fs.
215 if (sr_parse_period(contents, &p, &q) == SR_OK) {
216 ctx->samplerate = q / p;
218 /* Does not happen unless time value is non-standard */
219 sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
220 q, p, ctx->samplerate);
223 sr_dbg("Samplerate: %" PRIu64, ctx->samplerate);
225 sr_err("Parsing timescale failed.");
227 } else if (g_strcmp0(name, "var") == 0) {
228 /* Format: $var type size identifier reference $end */
229 gchar **parts = g_strsplit_set(contents, " \r\n\t", 0);
230 remove_empty_parts(parts);
232 if (g_strv_length(parts) != 4)
233 sr_warn("$var section should have 4 items");
234 else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
235 sr_info("Unsupported signal type: '%s'", parts[0]);
236 else if (strtol(parts[1], NULL, 10) != 1)
237 sr_info("Unsupported signal size: '%s'", parts[1]);
238 else if (ctx->channelcount >= ctx->maxchannels)
239 sr_warn("Skipping '%s' because only %d channels requested.", parts[3], ctx->maxchannels);
241 sr_info("Channel %d is '%s' identified by '%s'.", ctx->channelcount, parts[3], parts[2]);
242 vcd_ch = g_malloc(sizeof(struct vcd_channel));
243 vcd_ch->identifier = g_strdup(parts[2]);
244 vcd_ch->name = g_strdup(parts[3]);
245 ctx->channels = g_slist_append(ctx->channels, vcd_ch);
252 g_free(name); name = NULL;
253 g_free(contents); contents = NULL;
262 static int format_match(const char *filename)
265 gchar *name = NULL, *contents = NULL;
268 file = fopen(filename, "r");
273 * If we can parse the first section correctly,
274 * then it is assumed to be a VCD file.
276 status = parse_section(file, &name, &contents);
277 status = status && (*name != '\0');
286 static int init(struct sr_input *in, const char *filename)
288 struct sr_channel *ch;
290 char name[SR_MAX_CHANNELNAME_LEN + 1];
296 if (!(ctx = g_try_malloc0(sizeof(*ctx)))) {
297 sr_err("Input format context malloc failed.");
298 return SR_ERR_MALLOC;
301 num_channels = DEFAULT_NUM_CHANNELS;
307 param = g_hash_table_lookup(in->param, "numchannels");
309 num_channels = strtoul(param, NULL, 10);
310 if (num_channels < 1) {
311 release_context(ctx);
313 } else if (num_channels > 64) {
314 sr_err("No more than 64 channels supported.");
319 param = g_hash_table_lookup(in->param, "downsample");
321 ctx->downsample = strtoul(param, NULL, 10);
322 if (ctx->downsample < 1)
326 param = g_hash_table_lookup(in->param, "compress");
328 ctx->compress = strtoul(param, NULL, 10);
330 param = g_hash_table_lookup(in->param, "skip");
332 ctx->skip = strtoul(param, NULL, 10) / ctx->downsample;
335 /* Maximum number of channels to parse from the VCD */
336 ctx->maxchannels = num_channels;
338 /* Create a virtual device. */
339 in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
342 for (i = 0; i < num_channels; i++) {
343 snprintf(name, SR_MAX_CHANNELNAME_LEN, "%d", i);
345 if (!(ch = sr_channel_new(i, SR_CHANNEL_LOGIC, TRUE, name))) {
346 release_context(ctx);
350 in->sdi->channels = g_slist_append(in->sdi->channels, ch);
356 /* Send N samples of the given value. */
357 static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_t count)
359 struct sr_datafeed_packet packet;
360 struct sr_datafeed_logic logic;
361 uint64_t buffer[CHUNKSIZE];
363 unsigned chunksize = CHUNKSIZE;
365 if (count < chunksize)
368 for (i = 0; i < chunksize; i++)
371 packet.type = SR_DF_LOGIC;
372 packet.payload = &logic;
373 logic.unitsize = sizeof(uint64_t);
377 if (count < chunksize)
380 logic.length = sizeof(uint64_t) * chunksize;
382 sr_session_send(sdi, &packet);
387 /* Parse the data section of VCD */
388 static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct context *ctx)
390 GString *token = g_string_sized_new(32);
392 uint64_t prev_timestamp = 0;
393 uint64_t prev_values = 0;
395 /* Read one space-delimited token at a time. */
396 while (read_until(file, NULL, 'N') && read_until(file, token, 'W')) {
397 if (token->str[0] == '#' && g_ascii_isdigit(token->str[1])) {
398 /* Numeric value beginning with # is a new timestamp value */
400 timestamp = strtoull(token->str + 1, NULL, 10);
402 if (ctx->downsample > 1)
403 timestamp /= ctx->downsample;
406 * Skip < 0 => skip until first timestamp.
407 * Skip = 0 => don't skip
408 * Skip > 0 => skip until timestamp >= skip.
411 ctx->skip = timestamp;
412 prev_timestamp = timestamp;
413 } else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip) {
414 prev_timestamp = ctx->skip;
416 else if (timestamp == prev_timestamp) {
417 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
420 if (ctx->compress != 0 && timestamp - prev_timestamp > ctx->compress)
422 /* Compress long idle periods */
423 prev_timestamp = timestamp - ctx->compress;
426 sr_dbg("New timestamp: %" PRIu64, timestamp);
428 /* Generate samples from prev_timestamp up to timestamp - 1. */
429 send_samples(sdi, prev_values, timestamp - prev_timestamp);
430 prev_timestamp = timestamp;
432 } else if (token->str[0] == '$' && token->len > 1) {
433 /* This is probably a $dumpvars, $comment or similar.
434 * $dump* contain useful data, but other tags will be skipped until $end. */
435 if (g_strcmp0(token->str, "$dumpvars") == 0
436 || g_strcmp0(token->str, "$dumpon") == 0
437 || g_strcmp0(token->str, "$dumpoff") == 0
438 || g_strcmp0(token->str, "$end") == 0) {
439 /* Ignore, parse contents as normally. */
441 /* Skip until $end */
442 read_until(file, NULL, '$');
445 else if (strchr("bBrR", token->str[0]) != NULL) {
446 /* A vector value. Skip it and also the following identifier. */
447 read_until(file, NULL, 'N');
448 read_until(file, NULL, 'W');
449 } else if (strchr("01xXzZ", token->str[0]) != NULL) {
450 /* A new 1-bit sample value */
453 struct vcd_channel *vcd_ch;
455 bit = (token->str[0] == '1');
457 g_string_erase(token, 0, 1);
458 if (token->len == 0) {
459 /* There was a space between value and identifier.
462 read_until(file, NULL, 'N');
463 read_until(file, token, 'W');
466 for (i = 0, l = ctx->channels; i < ctx->channelcount && l; i++, l = l->next) {
469 if (g_strcmp0(token->str, vcd_ch->identifier) == 0) {
470 /* Found our channel */
472 prev_values |= (uint64_t)1 << i;
474 prev_values &= ~((uint64_t)1 << i);
480 if (i == ctx->channelcount)
481 sr_dbg("Did not find channel for identifier '%s'.", token->str);
483 sr_warn("Skipping unknown token '%s'.", token->str);
486 g_string_truncate(token, 0);
489 g_string_free(token, TRUE);
492 static int loadfile(struct sr_input *in, const char *filename)
494 struct sr_datafeed_packet packet;
495 struct sr_datafeed_meta meta;
496 struct sr_config *src;
503 if ((file = fopen(filename, "r")) == NULL)
506 if (!parse_header(file, ctx)) {
507 sr_err("VCD parsing failed");
512 /* Send header packet to the session bus. */
513 std_session_send_df_header(in->sdi, LOG_PREFIX);
515 /* Send metadata about the SR_DF_LOGIC packets to come. */
516 packet.type = SR_DF_META;
517 packet.payload = &meta;
518 samplerate = ctx->samplerate / ctx->downsample;
519 src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
520 meta.config = g_slist_append(NULL, src);
521 sr_session_send(in->sdi, &packet);
524 /* Parse the contents of the VCD file */
525 parse_contents(file, in->sdi, ctx);
527 /* Send end packet to the session bus. */
528 packet.type = SR_DF_END;
529 sr_session_send(in->sdi, &packet);
532 release_context(ctx);
538 SR_PRIV struct sr_input_format input_vcd = {
540 .description = "Value Change Dump",
541 .format_match = format_match,
543 .loadfile = loadfile,