USART always ready

src/devices/usart.rs

@@ -52,7 +52,35 @@ impl DeviceImpl for USART {
                 info!(self.log, "USART::Read(), not implemented");
                 0
             },
-            USART_STATUS => self.status,
+            USART_STATUS => {
+                // USART_DREIF_bm 0x20
+                /*
+
+                6528 #define USART_RXCIF_bm  0x80   // Receive Interrupt Flag bit mask.
+                6529 #define USART_RXCIF_bp  7   // Receive Interrupt Flag bit position.
+                6530
+                6531 #define USART_TXCIF_bm  0x40   // Transmit Interrupt Flag bit mask.
+                6532 #define USART_TXCIF_bp  6   // Transmit Interrupt Flag bit position.
+                6533
+                6534 #define USART_DREIF_bm  0x20   // Data Register Empty Flag bit mask.
+                6535 #define USART_DREIF_bp  5   // Data Register Empty Flag bit position.
+                6536
+                6537 #define USART_FERR_bm  0x10   // Frame Error bit mask.
+                6538 #define USART_FERR_bp  4   // Frame Error bit position.
+                6539
+                6540 #define USART_BUFOVF_bm  0x08   // Buffer Overflow bit mask.
+                6541 #define USART_BUFOVF_bp  3   // Buffer Overflow bit position.
+                6542
+                6543 #define USART_PERR_bm  0x04   // Parity Error bit mask.
+                6544 #define USART_PERR_bp  2   // Parity Error bit position.
+                6545
+                6546 #define USART_RXB8_bm  0x01   // Receive Bit 8 bit mask.
+                6547 #define USART_RXB8_bp  0   // Receive Bit 8 bit position.
+                6548
+                 */
+                info!(self.log, "Checking USART status");
+                self.status | 0x20u8  // Data register empty flag.
+            }
             USART_CTRLA => self.ctrla,
             USART_CTRLB => self.ctrlb,
             USART_CTRLC => self.ctrlc,