/*
* This file is part of the sigrok project.
*
- * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-/* Based on Verilog standard IEEE Std 1364-2001 Version C */
+/* The VCD input module has the following options:
+ *
+ * numprobes: Maximum number of probes to use. The probes are
+ * detected in the same order as they are listed
+ * in the $var sections of the VCD file.
+ *
+ * skip: Allows skipping until given timestamp in the file.
+ * This can speed up analyzing of long captures.
+ *
+ * Value < 0: Skip until first timestamp listed in
+ * the file. (default)
+ *
+ * Value = 0: Do not skip, instead generate samples
+ * beginning from timestamp 0.
+ *
+ * Value > 0: Start at the given timestamp.
+ *
+ * downsample: Divide the samplerate by the given factor.
+ * This can speed up analyzing of long captures.
+ *
+ * Based on Verilog standard IEEE Std 1364-2001 Version C
+ *
+ * Supported features:
+ * - $var with 'wire' and 'reg' types of scalar variables
+ * - $timescale definition for samplerate
+ * - multiple character variable identifiers
+ *
+ * Most important unsupported features:
+ * - vector variables (bit vectors etc.)
+ * - analog, integer and real number variables
+ * - $dumpvars initial value declaration
+ * - $scope namespaces
+ */
+
+/* */
#include <stdlib.h>
#include <glib.h>
static gboolean read_until(FILE *file, GString *dest, char mode)
{
char prev[4] = "";
+ long startpos = ftell(file);
for(;;)
{
int c = fgetc(file);
if (c == EOF)
{
- if (mode != 'N')
- sr_err("Unexpected EOF.");
+ if (mode == '$')
+ sr_err("Unexpected EOF, read started at %ld.", startpos);
return FALSE;
}
uint64_t samplerate;
int maxprobes;
int probecount;
+ int downsample;
+ int64_t skip;
struct probe probes[SR_MAX_NUM_PROBES];
};
if (period.q % period.p != 0)
{
/* Does not happen unless time value is non-standard */
- sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 ".",
+ sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
period.q, period.p, ctx->samplerate);
}
if (g_strv_length(parts) != 4)
{
- sr_err("$var section should have 4 items");
+ sr_warn("$var section should have 4 items");
}
else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
{
- sr_warn("Unsupported signal type: '%s'", parts[0]);
+ sr_info("Unsupported signal type: '%s'", parts[0]);
}
else if (strtol(parts[1], NULL, 10) != 1)
{
- sr_warn("Unsupported signal size: '%s'", parts[1]);
+ sr_info("Unsupported signal size: '%s'", parts[1]);
}
else if (ctx->probecount >= ctx->maxprobes)
{
num_probes = DEFAULT_NUM_PROBES;
ctx->samplerate = 0;
+ ctx->downsample = 1;
+ ctx->skip = -1;
if (in->param) {
param = g_hash_table_lookup(in->param, "numprobes");
return SR_ERR;
}
}
+
+ param = g_hash_table_lookup(in->param, "downsample");
+ if (param) {
+ ctx->downsample = strtoul(param, NULL, 10);
+ if (ctx->downsample < 1)
+ {
+ ctx->downsample = 1;
+ }
+ }
+
+ param = g_hash_table_lookup(in->param, "skip");
+ if (param) {
+ ctx->skip = strtoul(param, NULL, 10) / ctx->downsample;
+ }
}
/* Maximum number of probes to parse from the VCD */
uint64_t buffer[CHUNKSIZE];
uint64_t i;
unsigned chunksize = CHUNKSIZE;
-
+
if (count < chunksize)
chunksize = count;
{
GString *token = g_string_sized_new(32);
- gboolean first = TRUE;
uint64_t prev_timestamp = 0;
uint64_t prev_values = 0;
uint64_t timestamp;
timestamp = strtoull(token->str + 1, NULL, 10);
- if (first)
+ if (ctx->downsample > 1)
+ timestamp /= ctx->downsample;
+
+ /* Skip < 0 => skip until first timestamp.
+ * Skip = 0 => don't skip
+ * Skip > 0 => skip until timestamp >= skip.
+ */
+ if (ctx->skip < 0)
+ {
+ ctx->skip = timestamp;
+ prev_timestamp = timestamp;
+ }
+ else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip)
{
- first = FALSE;
+ prev_timestamp = ctx->skip;
+ }
+ else if (timestamp == prev_timestamp)
+ {
+ /* Ignore repeated timestamps (e.g. sigrok outputs these) */
}
else
{
/* Generate samples from prev_timestamp up to timestamp - 1. */
send_samples(sdi, prev_values, timestamp - prev_timestamp);
+ prev_timestamp = timestamp;
}
-
- prev_timestamp = timestamp;
}
- else if (token->str[0] == '$')
+ else if (token->str[0] == '$' && token->len > 1)
{
/* This is probably a $dumpvars, $comment or similar.
- * For now, just skip it until $end. */
- read_until(file, NULL, '$');
+ * $dump* contain useful data, but other tags will be skipped until $end. */
+ if (g_strcmp0(token->str, "$dumpvars") == 0 ||
+ g_strcmp0(token->str, "$dumpon") == 0 ||
+ g_strcmp0(token->str, "$dumpoff") == 0 ||
+ g_strcmp0(token->str, "$end") == 0)
+ {
+ /* Ignore, parse contents as normally. */
+ }
+ else
+ {
+ /* Skip until $end */
+ read_until(file, NULL, '$');
+ }
+ }
+ else if (strchr("bBrR", token->str[0]) != NULL)
+ {
+ /* A vector value. Skip it and also the following identifier. */
+ read_until(file, NULL, 'N');
+ read_until(file, NULL, 'W');
}
else if (strchr("01xXzZ", token->str[0]) != NULL)
{
if (i == ctx->probecount)
{
- sr_info("Did not find probe for identifier '%s'.", token->str);
+ sr_dbg("Did not find probe for identifier '%s'.", token->str);
}
}
+ else
+ {
+ sr_warn("Skipping unknown token '%s'.", token->str);
+ }
g_string_truncate(token, 0);
}
/* Send metadata about the SR_DF_LOGIC packets to come. */
packet.type = SR_DF_META_LOGIC;
packet.payload = &meta;
- meta.samplerate = ctx->samplerate;
+ meta.samplerate = ctx->samplerate / ctx->downsample;
meta.num_probes = ctx->probecount;
sr_session_send(in->sdi, &packet);
projects / libsigrok.git / blobdiff