X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fhardware%2Fasix-sigma%2Fprotocol.c;h=db89d6890a9c2d9d1f214de5d0335f297719d5b5;hb=9a0a606a8215aa7fd41bb72a3653dff7ef54505b;hp=d2670b4c3a974e503330f9a1564fd2b1737772e1;hpb=7c86d8537204caa95d70d92bf5698b32ac35fa10;p=libsigrok.git

diff --git a/src/hardware/asix-sigma/protocol.c b/src/hardware/asix-sigma/protocol.c
index d2670b4c..db89d689 100644
--- a/src/hardware/asix-sigma/protocol.c
+++ b/src/hardware/asix-sigma/protocol.c
@@ -519,6 +519,30 @@ static int upload_firmware(struct sr_context *ctx,
 	return SR_OK;
 }
 
+/*
+ * Sigma doesn't support limiting the number of samples, so we have to
+ * translate the number and the samplerate to an elapsed time.
+ *
+ * In addition we need to ensure that the last data cluster has passed
+ * the hardware pipeline, and became available to the PC side. With RLE
+ * compression up to 327ms could pass before another cluster accumulates
+ * at 200kHz samplerate when input pins don't change.
+ */
+SR_PRIV uint64_t sigma_limit_samples_to_msec(const struct dev_context *devc,
+					     uint64_t limit_samples)
+{
+	uint64_t limit_msec;
+	uint64_t worst_cluster_time_ms;
+
+	limit_msec = limit_samples * 1000 / devc->cur_samplerate;
+	worst_cluster_time_ms = 65536 * 1000 / devc->cur_samplerate;
+	/*
+	 * One cluster time is not enough to flush pipeline when sampling
+	 * grounded pins with 1 sample limit at 200kHz. Hence the 2* fix.
+	 */
+	return limit_msec + 2 * worst_cluster_time_ms;
+}
+
 SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t samplerate)
 {
 	struct dev_context *devc;
@@ -574,7 +598,7 @@ SR_PRIV int sigma_set_samplerate(const struct sr_dev_inst *sdi, uint64_t sampler
 	 */
 	if (ret == SR_OK && devc->limit_samples) {
 		uint64_t msecs;
-		msecs = devc->limit_samples * 1000 / devc->cur_samplerate;
+		msecs = sigma_limit_samples_to_msec(devc, devc->limit_samples);
 		devc->limit_msec = msecs;
 	}
 
@@ -723,7 +747,7 @@ static void sigma_decode_dram_cluster(struct sigma_dram_cluster *dram_cluster,
 
 	ts = sigma_dram_cluster_ts(dram_cluster);
 	tsdiff = ts - ss->lastts;
-	ss->lastts = ts;
+	ss->lastts = ts + EVENTS_PER_CLUSTER;
 
 	packet.type = SR_DF_LOGIC;
 	packet.payload = &logic;
@@ -741,7 +765,7 @@ static void sigma_decode_dram_cluster(struct sigma_dram_cluster *dram_cluster,
 	 * sample in the cluster happens at the time of the timestamp
 	 * and the remaining samples happen at timestamp +1...+6 .
 	 */
-	for (ts = 0; ts < tsdiff - (EVENTS_PER_CLUSTER - 1); ts++) {
+	for (ts = 0; ts < tsdiff; ts++) {
 		i = ts % 1024;
 		samples[2 * i + 0] = ss->lastsample & 0xff;
 		samples[2 * i + 1] = ss->lastsample >> 8;
@@ -751,7 +775,7 @@ static void sigma_decode_dram_cluster(struct sigma_dram_cluster *dram_cluster,
 		 * end of submitting the padding samples, submit
 		 * the packet to Sigrok.
 		 */
-		if ((i == 1023) || (ts == (tsdiff - EVENTS_PER_CLUSTER))) {
+		if ((i == 1023) || (ts == tsdiff - 1)) {
 			logic.length = (i + 1) * logic.unitsize;
 			sr_session_send(sdi, &packet);
 		}