1 files changed, 18 insertions, 0 deletions
diff --git a/supervia.c b/supervia.c
new file mode 100644
index 0000000..23e44e9
--- /dev/null
+++ b/supervia.c
@@ -0,0 +1,18 @@
+void init_supervia(struct supervia *sv) {
+	memset(sv, 0, sizeof(struct supervia));
+}
+
+/* Shifts out one bit from each output byte of the shift register into
+ * the serial output lines of those output bytes.
+ */
+void shift_out8(struct supervia *sv, int id) {
+	uint8_t bitpos = 7-sv->sr[id].ocount;
+	for (int i = 0; i < 8; i++) {
+		if (sv->sr[id].dir & (1 << i)) {
+			uint8_t bit = (sv->sr[id].data.u8[i] >> bitpos) & 1;
+			sv->sr[id].bits |= (bit << i);
+		}
+	}
+	sv->sr[id].ocount++;
+	sv->sr[id].ocount %= 8;
+}