# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1539965107 -7200
# Node ID f56fc460bc08d37983c11514ce68311679df0243
# Parent  0f9eb8bc112d20aea4fe6d07ed1772b7876ec433
Introduced some UART convenience functions.

diff -r 0f9eb8bc112d -r f56fc460bc08 debug.c
--- a/debug.c	Fri Oct 19 17:50:59 2018 +0200
+++ b/debug.c	Fri Oct 19 18:05:07 2018 +0200
@@ -20,7 +20,7 @@
 #include "pic32_c.h"
 #include "debug.h"
 
-/* Value output functions. */
+/* Value output functions using UART1. */
 
 void bits(uint32_t reg)
 {
@@ -59,13 +59,39 @@
     uart_write('\n');
 }
 
-/* General output functions. */
+
+
+/* General input/output functions. */
+
+int uart_can_read(int uart)
+{
+    return REG(UART_REG(uart, UxSTA)) & 1;
+}
+
+char uart_read_char(int uart)
+{
+    return (char) REG(UART_REG(uart, UxRXREG));
+}
+
+int uart_can_write(int uart)
+{
+    return !(REG(UART_REG(uart, UxSTA)) & (1 << 9)); /* UTXBF (buffer full) */
+}
+
+void uart_write_char(int uart, char c)
+{
+    while (!uart_can_write(uart)); /* busy loop */
+
+    REG(UART_REG(uart, UxTXREG)) = c;
+}
+
+
+
+/* Functions using UART1. */
 
 void uart_write(char c)
 {
-    while (REG(UART_REG(1, UxSTA)) & (1 << 9)); /* UTXBF (buffer full) */
-
-    REG(UART_REG(1, UxTXREG)) = c;
+    uart_write_char(1, c);
 }
 
 void uart_write_string(const char *s)
diff -r 0f9eb8bc112d -r f56fc460bc08 debug.h
--- a/debug.h	Fri Oct 19 17:50:59 2018 +0200
+++ b/debug.h	Fri Oct 19 18:05:07 2018 +0200
@@ -20,9 +20,21 @@
 #ifndef __DEBUG_H__
 #define __DEBUG_H__
 
+/* Value output functions using UART1. */
+
 void bits(uint32_t reg);
 void vbits(uint32_t val);
 void vhex(uint32_t val);
+
+/* General input/output functions. */
+
+int uart_can_read(int uart);
+char uart_read_char(int uart);
+int uart_can_write(int uart);
+void uart_write_char(int uart, char c);
+
+/* Functions using UART1. */
+
 void uart_write(char c);
 void uart_write_string(const char *s);
 
diff -r 0f9eb8bc112d -r f56fc460bc08 main.c
--- a/main.c	Fri Oct 19 17:50:59 2018 +0200
+++ b/main.c	Fri Oct 19 18:05:07 2018 +0200
@@ -132,7 +132,8 @@
 
 void interrupt_handler(void)
 {
-    uint32_t ifs, val;
+    uint32_t ifs;
+    char val;
 
     /* Check for a UART receive interrupt condition (UxRIF). */
 
@@ -146,11 +147,11 @@
 
         /* Write the received data back. */
 
-        while (REG(UART_REG(1, UxSTA)) & 1)
+        while (uart_can_read(1))
         {
-            val = REG(UART_REG(1, UxRXREG));
+            val = uart_read_char(1);
             if (uart_echo)
-                uart_write((char) val);
+                uart_write_char(1, val);
 
             /* Initiate transfer upon receiving a particular character. */