X-Git-Url: https://git.ucc.asn.au/?p=uccvend-snackrom.git;a=blobdiff_plain;f=ROM2%2Fsci.c;h=d7c9f287df6f4c84918681b88b159855b6ddaac0;hp=668e865d646e09a02dc0c18ca74aa0523a08a1de;hb=f5bc521c83d95d35e852747402a44d1411252c2b;hpb=17af89d1b2f699e0fc9dbe6132b6b8e0c6c81068

diff --git a/ROM2/sci.c b/ROM2/sci.c
index 668e865..d7c9f28 100644
--- a/ROM2/sci.c
+++ b/ROM2/sci.c
@@ -5,6 +5,7 @@ char sci_tx_buf[BUFFER_LEN];
 volatile char sci_rx_buf[BUFFER_LEN];
 volatile bool sci_have_packet;
 volatile u8 sci_rx_buf_ptr;
+volatile bool sci_echo;
 
 void sci_init() {
 	/* assumes clock of 4.91Mhz */
@@ -18,9 +19,10 @@ void sci_init() {
 
 	sci_have_packet = 0;
 	sci_rx_buf_ptr = 0;
+	sci_echo = 0;
 }
 
-void send_packet() {
+void send_buffer(bool crlf) {
 	char* c;
 	for (c = sci_tx_buf; *c; c++) {
 		/* wait for TX ready */
@@ -29,28 +31,44 @@ void send_packet() {
 		/* send byte */
 		_io_ports[M6811_SCDR] = *c;
 	}
+	if (!crlf) return;
+	/* send CRLF */
+	while (!(_io_ports[M6811_SCSR] & M6811_TDRE));
+	_io_ports[M6811_SCDR] = '\r';
+	while (!(_io_ports[M6811_SCSR] & M6811_TDRE));
+	_io_ports[M6811_SCDR] = '\n';
+}
+
+void send_string(char* c) {
+	for (; *c; c++) {
+		while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TX ready */
+		_io_ports[M6811_SCDR] = *c; /* send byte */
+	}
 }
 
 void sci_rx_int() {
+	char buf = _io_ports[M6811_SCDR];
+	if (sci_echo) {
+		while (!(_io_ports[M6811_SCSR] & M6811_TDRE)); /* wait for TX ready */
+		_io_ports[M6811_SCDR] = buf; /* send byte */
+	}
+
 	/* XXX FIXME we should do something about errors. nack? */
 	if (sci_have_packet) {
 		/* overrun :( */
-		_io_ports[M6811_SCDR]; /* read it anyway */
 		return;
 	}
-	sci_rx_buf[sci_rx_buf_ptr] = _io_ports[M6811_SCDR];
-	if (sci_rx_buf[sci_rx_buf_ptr] == '\n' ||
-			sci_rx_buf[sci_rx_buf_ptr] == '\r') {
-		if (sci_rx_buf_ptr == 0) return; /* we've read a blank packet in */
+	sci_rx_buf[sci_rx_buf_ptr] = buf;
+
+	if (buf == '\n' || buf == '\r') {
 		sci_rx_buf[sci_rx_buf_ptr] = '\0';
 		sci_have_packet = 1;
-		sci_rx_buf_ptr = 0;
 	}
-	sci_rx_buf_ptr++;
-	if (sci_rx_buf_ptr >= BUFFER_LEN) {
-		sci_rx_buf[BUFFER_LEN] = '\0'; /* this is as much as we could fit */
-		sci_have_packet = 1;
-		sci_rx_buf_ptr = 0;
+
+	if (sci_rx_buf_ptr+1 < BUFFER_LEN)
+		sci_rx_buf_ptr++;
+	else {
+		sci_rx_buf[BUFFER_LEN-1] = '\0'; /* this is as much as we could fit */
 	}
 }
 
@@ -67,11 +85,9 @@ void msg_clr() {
 }
 
 void send_ack() {
-	my_strncpy(sci_tx_buf, "!\n", BUFFER_LEN);
-	send_packet();
+	send_string("!" CRLF);
 }
 
 void send_nack() {
-	my_strncpy(sci_tx_buf, "?\n", BUFFER_LEN);
-	send_packet();
+	send_string("?" CRLF);
 }