From: Petteri Aimonen Date: Wed, 21 Nov 2012 14:28:55 +0000 (+0200) Subject: Add downsample and skip parameters to input/vcd. X-Git-Tag: dsupstream~534 X-Git-Url: https://sigrok.org/gitweb/?p=libsigrok.git;a=commitdiff_plain;h=0157808d740ec11f3a94f2d147b4429bd2a9954d Add downsample and skip parameters to input/vcd. --- diff --git a/input/vcd.c b/input/vcd.c index 5ad9ad6c..b8b46979 100644 --- a/input/vcd.c +++ b/input/vcd.c @@ -1,7 +1,7 @@ /* * This file is part of the sigrok project. * - * Copyright (C) 2010-2012 Bert Vermeulen + * Copyright (C) 2012 Petteri Aimonen * * 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 @@ -17,7 +17,40 @@ * along with this program. If not, see . */ -/* 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 + */ + +/* */ #include #include @@ -131,6 +164,8 @@ struct context uint64_t samplerate; int maxprobes; int probecount; + int downsample; + int64_t skip; struct probe probes[SR_MAX_NUM_PROBES]; }; @@ -192,7 +227,7 @@ static gboolean parse_header(FILE *file, struct context *ctx) 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); } @@ -284,6 +319,8 @@ static int init(struct sr_input *in) 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"); @@ -295,6 +332,20 @@ static int init(struct sr_input *in) 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 */ @@ -329,7 +380,7 @@ static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_ uint64_t buffer[CHUNKSIZE]; uint64_t i; unsigned chunksize = CHUNKSIZE; - + if (count < chunksize) chunksize = count; @@ -360,8 +411,8 @@ static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct con { GString *token = g_string_sized_new(32); - gboolean first = TRUE; uint64_t prev_timestamp = 0; + uint64_t new_values = 0; uint64_t prev_values = 0; /* Read one space-delimited token at a time. */ @@ -373,19 +424,40 @@ static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct con 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; + } + else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip) { - first = FALSE; + prev_timestamp = ctx->skip - 1; + } + else if (timestamp == prev_timestamp) + { + /* This only occurs when ctx->downsample > 1 */ + if (prev_values != new_values) + { + sr_warn("VCD downsampling hides a glitch at %" PRIu64, timestamp); + prev_values = new_values; + } } else { sr_dbg("New timestamp: %" PRIu64, timestamp); /* Generate samples from prev_timestamp up to timestamp - 1. */ - send_samples(sdi, prev_values, timestamp - prev_timestamp); + send_samples(sdi, new_values, timestamp - prev_timestamp); + + prev_timestamp = timestamp; + prev_values = new_values; } - - prev_timestamp = timestamp; } else if (token->str[0] == '$') { @@ -417,9 +489,9 @@ static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct con /* Found our probe */ if (bit) - prev_values |= (1 << i); + new_values |= (1 << i); else - prev_values &= ~(1 << i); + new_values &= ~(1 << i); break; } @@ -467,7 +539,7 @@ static int loadfile(struct sr_input *in, const char *filename) /* 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);