Got the DMA to send a simple message through UART2.

1 files changed, 33 insertions, 5 deletions

diff --git a/02-usart/include/usart.h b/02-usart/include/usart.h
index d806397..c645e92 100644
--- a/02-usart/include/usart.h
+++ b/02-usart/include/usart.h
@@ -6,6 +6,7 @@
 
 #include "common.h"
 #include "rcc.h"
+#include <assert.h>
 
 #define USART1 (* (__IO usart_t*) USART1_BASE)
 #define USART2 (* (__IO usart_t*) USART2_BASE)
@@ -23,7 +24,7 @@ typedef enum {
 typedef struct {
   /* USART configuration registers 0x04 - 0x0c. */
   union {
-    uint32_t c_r1;
+    __IO uint32_t c_r1;
     struct {
       bits_t ue:1;     /* UART enable */
       bits_t uesm:1;   /* UART enabled in stop mode. */
@@ -49,10 +50,10 @@ typedef struct {
       bits_t reserved:3;
     } PACKED c1_bf; /* c1_bf = c1 bit field */
   }; /* USART Control Register 1. */
-  uint32_t c_r2;
+  __IO uint32_t c_r2;
 
   union {
-    uint32_t c_r3;
+    __IO uint32_t c_r3;
     struct {
       bits_t eie:1;   // Error interrupt enable. 
       bits_t iren:1;  // IrDA mode enabled
@@ -88,7 +89,7 @@ typedef struct {
 
   /* USART ISR register. Offset = 0x1c*/
   union {
-    uint32_t is_r; /* Interrupt service register. */
+    __IO uint32_t is_r; /* Interrupt service register. */
     struct {
       bits_t pe:1;    // Parity error
       bits_t fe:1;    // Framing error
@@ -118,11 +119,36 @@ typedef struct {
       bits_t reserved2:6;
     } PACKED is_bf; /* Interrupt servite bit field. */
   };
-  uint32_t ic_r;
+  union {
+    __IO uint32_t ic_r;
+    struct {
+      bits_t pecf:1; // Parity error clear flag
+      bits_t fecf:1; // Framing error clear flag
+      bits_t ncf:1; // Noise detected clear flag
+      bits_t orecf:1; // Overrun error clear flag
+      bits_t idlecf:1; // Idle line detected clear flag
+      bits_t reserved0:1;
+      bits_t tccf:1; // Transmission complete clear flag
+      bits_t tcbgtcf:1; // Transmission completed before guard time clear flag
+      bits_t lbdcf:1; // LIN break detection clear flag
+      bits_t ctscf:1; // CTS clear flag
+      bits_t reserved1:1;
+      bits_t rtocf:1; // Receiver timeout clear flag
+      bits_t eobcf:1; // End of block clear flag
+      bits_t reserved2:4;
+      bits_t cmcf:1; // Character match clear flag
+      bits_t reserved3:2; // Character match clear flag
+      bits_t wucf:1; // Wakeup from Stop mode clear flag.
+      bits_t reserved4:11;
+    } PACKED ic_bf;
+  };
   uint32_t rd_r;
   uint32_t td_r;
 } usart_t;
 
+static_assert(offsetof(usart_t, ic_r) == 0x20, "Offset assertion failed.");
+static_assert(offsetof(usart_t, rd_r) == 0x24, "Offset assertion failed.");
+
 typedef enum {
   OVERSAMPLE_8,
   OVERSAMPLE_16
@@ -170,6 +196,8 @@ void usart_set_parity(__IO usart_t* usart, usart_parity_t parity);
 
 void usart_set_enabled(__IO usart_t* usart, usart_enable_t enabled);
 
+void usart_enable_dma(__IO usart_t* usart, usart_enable_t enabled);
+
 /*
  * Send a byte on the usart, This command blocks until the data
  * is fully sent.