Use Chain for dsptools example.

Rename examples, bump dsptools to master, and incorporate feedback.

tests/streaming-fir.c

@@ -0,0 +1,65 @@
+#define PASSTHROUGH_WRITE 0x2000
+#define PASSTHROUGH_WRITE_COUNT 0x2008
+#define PASSTHROUGH_READ 0x2100
+#define PASSTHROUGH_READ_COUNT 0x2108
+
+#define BP 3
+#define BP_SCALE ((double)(1 << BP))
+
+#include "mmio.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+
+uint64_t roundi(double x)
+{
+  if (x < 0.0) {
+    return (uint64_t)(x - 0.5);
+  } else {
+    return (uint64_t)(x + 0.5);
+  }
+}
+
+int main(void)
+{
+  double test_vector[15] = {1.0, 2.0, 3.0, 4.0, 5.0, 4.0, 3.0, 2.0, 1.0, 0.5, 0.25, 0.125, 0.125};
+  uint32_t num_tests = sizeof(test_vector) / sizeof(double);
+  printf("Starting writing %d inputs\n", num_tests);
+
+  for (int i = 0; i < num_tests; i++) {
+    reg_write64(PASSTHROUGH_WRITE, roundi(test_vector[i] * BP_SCALE));
+  }
+
+  printf("Done writing\n");
+  uint32_t rcnt = reg_read32(PASSTHROUGH_READ_COUNT);
+  printf("Write count: %d\n", reg_read32(PASSTHROUGH_WRITE_COUNT));
+  printf("Read count: %d\n", rcnt);
+
+  int failed = 0;
+  if (rcnt != 0) {
+    for (int i = 0; i < num_tests - 3; i++) {
+      uint32_t res = reg_read32(PASSTHROUGH_READ);
+      // double res = ((double)reg_read32(PASSTHROUGH_READ)) / BP_SCALE;
+      double expected_double = 3*test_vector[i] + 2*test_vector[i+1] + test_vector[i+2];
+      uint32_t expected = ((uint32_t)(expected_double * BP_SCALE + 0.5)) & 0xFF;
+      if (res == expected) {
+        printf("\n\nPass: Got %u Expected %u\n\n", res, expected);
+      } else {
+        failed = 1;
+        printf("\n\nFail: Got %u Expected %u\n\n", res, expected);
+      }
+    }
+  } else {
+    failed = 1;
+  }
+
+  if (failed) {
+    printf("\n\nSome tests failed\n\n");
+  } else {
+    printf("\n\nAll tests passed\n\n");
+  }
+  
+  return 0;
+}