X-Git-Url: https://oss.titaniummirror.com/gitweb/?a=blobdiff_plain;f=tos%2Fchips%2Fmsp430%2Fusci%2FHplMsp430UsciInt1P.nc;h=1e18eb70bf9605c83845b19f4e219bb2a557b63b;hb=a4c683fb39c46c4a0382866e7ca1ab65a524fcf4;hp=c083cdb9a637d7dfa4847b11cc78cdfd79713c06;hpb=97db9cf16631f784eea3fc7a3ec925f09bc65c08;p=tinyos-2.x.git

diff --git a/tos/chips/msp430/usci/HplMsp430UsciInt1P.nc b/tos/chips/msp430/usci/HplMsp430UsciInt1P.nc
index c083cdb9..1e18eb70 100644
--- a/tos/chips/msp430/usci/HplMsp430UsciInt1P.nc
+++ b/tos/chips/msp430/usci/HplMsp430UsciInt1P.nc
@@ -26,13 +26,13 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
- 
+
 /**
  * HPL interrupt interface for the USCI1 peripheral.
- * 
+ *
  * @author R. Steve McKown <rsmckown@gmail.com>
  */
- 
+
 #include "Msp430Usci.h"
 #include "msp430hardware.h"
 
@@ -55,40 +55,59 @@ implementation
   MSP430REG_NORACE(UCB1RXBUF);
 #endif
 
-  /* This USCI_Ax and USCI_Bx interrupt vector signals receive events for UART
-   * and SPI modes, and status events for I2C modes.  Only Bx can do I2C.
+  /* This interrupt vector signals receive events.  USCI_A1 can receive events
+   * for UART and SPI modes, while USCI_B1 can receive events for I2C and SPI
+   * modes.
    */
   TOSH_SIGNAL(USCIAB1RX_VECTOR) {
-    if (READ_FLAG(UC1IFG, UCA1RXIFG)) {
+    if (READ_FLAG(UC1IFG & UC1IE, UCA1RXIE)) {
       volatile uint8_t c = UCA1RXBUF; /* read to clear UCA1RXIFG */
       if (READ_FLAG(UCA1CTL1, UCBRK)) {
-	UCA1CTL1 &= ~UCBRK;
+	CLR_FLAG(UCA1CTL1, UCBRK);
 	if (READ_FLAG(UCA1CTL0, UCMODE_3) == UCMODE_3)
-	  UCA1CTL1 &= ~UCDORM;
+	  CLR_FLAG(UCA1CTL1, UCDORM);
 	signal IntA.brk();
       } else
 	signal IntA.rx(c);
-    } else if (READ_FLAG(UC1IFG, UCB1RXIFG))
+    } else if (READ_FLAG(UC1IFG & UC1IE, UCB1RXIE)) {
       signal IntB.rx(UCB1RXBUF); /* read clears UCB1RXIFG */
-    else if (READ_FLAG(UCB1STAT, UCALIFG))
+
+    /* FIXME: the arbitration of I2C interrupts are not vetted.  If, for example
+     * the UCALIFG bit gets set and neither it nor the corresponding interrupt
+     * enable bit is never unset, then an ISR configured for UCSTTIFG or
+     * UCSTPIFG will never be signalled.
+     */
+
+    } else if (READ_FLAG(UCB1STAT, UCALIFG)) {
+      CLR_FLAG(UCB1STAT, UCALIFG);
       signal IntB.i2cCal();
-    else if (READ_FLAG(UCB1STAT, UCNACKIFG))
-      signal IntB.i2cNak();
-    else if (READ_FLAG(UCB1STAT, UCSTTIFG))
+    } else if (READ_FLAG(UCB1STAT, UCNACKIFG)) {
+      CLR_FLAG(UCB1STAT, UCNACKIFG);
+      CLR_FLAG(UC1IFG, UCB1TXIFG); /* Errata USCI25; 'reset' means clear? */
+      signal IntB.i2cNack();
+    } else if (READ_FLAG(UCB1STAT, UCSTTIFG)) {
+      CLR_FLAG(UCB1STAT, UCSTTIFG);
       signal IntB.i2cStart();
-    else if (READ_FLAG(UCB1STAT, UCSTPIFG))
+    } else if (READ_FLAG(UCB1STAT, UCSTPIFG)) {
+      CLR_FLAG(UCB1STAT, UCSTPIFG);
       signal IntB.i2cStop();
+    }
   }
-  
-  /* This USCI_Ax and USCI_Bx interrupt vector signals transmit events for UART
-   * and SPI modes, and rx/tx events for I2C modes.  Only Bx can do I2C.
+
+  /* This interrupt vector signals transmit events.  USCI_A1 can receive events
+   * for UART and SPI modes, while USCI_B1 can receive events for I2C and SPI
+   * modes.
    */
   TOSH_SIGNAL(USCIAB1TX_VECTOR) {
-    if (READ_FLAG(UC1IFG, UCB1RXIFG))
-      signal IntB.rx(UCB1RXBUF); /* I2C receive */
-    else if (READ_FLAG(UC1IFG, UCA1TXIFG))
+    if (READ_FLAG(UC1IFG & UC1IE, UCB1RXIE))
+      /* I2C receive.  Do not read UCB1RXBUF here, as the code receiving
+       * IntB.rx() may first need to set stop and/or start bits.  The receiver
+       * must read UCB1RXBUF.
+       */
+      signal IntB.rx(0);
+    else if (READ_FLAG(UC1IFG & UC1IE, UCA1TXIFG))
       signal IntA.tx();
-    else if (READ_FLAG(UC1IFG, UCB1TXIFG))
+    else if (READ_FLAG(UC1IFG & UC1IE, UCB1TXIFG))
       signal IntB.tx();
   }
 
@@ -97,15 +116,16 @@ implementation
   default async event void IntA.tx() {}
   /* i2c is not available for A devices, so the below are never signalled */
   default async event void IntA.i2cCal() {}
-  default async event void IntA.i2cNak() {}
+  default async event void IntA.i2cNack() {}
   default async event void IntA.i2cStart() {}
   default async event void IntA.i2cStop() {}
 
+  /* UART is not available for B devices, so IntB.brk() is never sitnalled */
   default async event void IntB.brk() {}
   default async event void IntB.rx(uint8_t byte) {}
   default async event void IntB.tx() {}
   default async event void IntB.i2cCal() {}
-  default async event void IntB.i2cNak() {}
+  default async event void IntB.i2cNack() {}
   default async event void IntB.i2cStart() {}
   default async event void IntB.i2cStop() {}
 }