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[uccvend-snackrom.git] / ROM2 / sci.c

diff --git a/ROM2/sci.c b/ROM2/sci.c
index 39006bc..739d706 100644 (file)
--- a/ROM2/sci.c
+++ b/ROM2/sci.c
@@ -1,11 +1,80 @@
 #include "vend.h"
+#include "chime.h"
 #include "sci.h"
 
+char sci_tx_buf[BUFFER_LEN];
+volatile char sci_rx_buf[BUFFER_LEN];
+volatile bool sci_have_packet;
+volatile u8 sci_rx_buf_ptr;
+
 void sci_init() {
-       _io_ports[M6811_BAUD] = M6811_DEF_BAUD;
+       /* assumes clock of 4.91Mhz */
+       _io_ports[M6811_BAUD] = 0x03; /* 9600 baud */
+
        /* Setup character format 1 start, 8-bits, 1 stop.  */
        _io_ports[M6811_SCCR1] = 0;
 
-       /* Enable reciever and transmitter.  */
-       _io_ports[M6811_SCCR2] = 0xc;
+       /* Enable reciever and transmitter & rx interrupt.  */
+       _io_ports[M6811_SCCR2] = M6811_RIE | M6811_TE | M6811_RE;
+
+       sci_have_packet = 0;
+       sci_rx_buf_ptr = 0;
+}
+
+void send_packet() {
+       char* c;
+       for (c = sci_tx_buf; *c; c++) {
+               /* wait for TX ready */
+               while (!(_io_ports[M6811_SCSR] & M6811_TDRE));
+
+               /* send byte */
+               _io_ports[M6811_SCDR] = *c;
+       }
+}
+
+void sci_rx_int() {
+       /* 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] = '\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;
+       }
+}
+
+void sci_interrupt_serial() {
+       chime_start();
+
+       if (_io_ports[M6811_SCSR] & M6811_RDRF) sci_rx_int();
+
+       if (_io_ports[M6811_SCSR] & M6811_OR)
+               _io_ports[M6811_SCDR]; /* declare it a lost cause */
+}
+
+void msg_clr() {
+       sci_have_packet = 0;
+       sci_rx_buf_ptr = 0;
+}
+
+void send_ack() {
+       my_strncpy(sci_tx_buf, "!\n", BUFFER_LEN);
+       send_packet();
+}
+
+void send_nack() {
+       my_strncpy(sci_tx_buf, "?\n", BUFFER_LEN);
+       send_packet();
 }