X-Git-Url: https://oss.titaniummirror.com/gitweb/?a=blobdiff_plain;f=tos%2Fchips%2Fmsp430%2Fusci%2FHplMsp430UsciInt0P.nc;fp=tos%2Fchips%2Fmsp430%2Fusci%2FHplMsp430UsciInt0P.nc;h=9e69649cd7701f039c4fa3e132a562e394d956bd;hb=12c6d873092b40119e4d556b3064e94aa21c0bbb;hp=65ee5be1494f7c4a4e8269396197e2bd344d8a08;hpb=4845da46c1bc60e3421abf4badf38abd4559a036;p=tinyos-2.x.git

diff --git a/tos/chips/msp430/usci/HplMsp430UsciInt0P.nc b/tos/chips/msp430/usci/HplMsp430UsciInt0P.nc
index 65ee5be1..9e69649c 100644
--- a/tos/chips/msp430/usci/HplMsp430UsciInt0P.nc
+++ b/tos/chips/msp430/usci/HplMsp430UsciInt0P.nc
@@ -62,40 +62,55 @@ implementation
   MSP430REG_NORACE(UCB0RXBUF);
 #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_A0 can receive events
+   * for UART and SPI modes, while USCI_B0 can receive events for I2C and SPI
+   * modes.
    */
   TOSH_SIGNAL(USCIAB0RX_VECTOR) {
-    if (READ_FLAG(UC0IFG, UCA0RXIFG)) {
+    if (READ_FLAG(UC0IFG & UC0IE, UCA0RXIE)) {
       volatile uint8_t c = UCA0RXBUF; /* read to clear UCA0RXIFG */
       if (READ_FLAG(UCA0CTL1, UCBRK)) {
-	UCA0CTL1 &= ~UCBRK;
+	CLR_FLAG(UCA0CTL1, UCBRK);
 	if (READ_FLAG(UCA0CTL0, UCMODE_3) == UCMODE_3)
-	  UCA0CTL1 &= ~UCDORM;
+	  CLR_FLAG(UCA0CTL1, UCDORM);
 	signal IntA.brk();
       } else
 	signal IntA.rx(c);
-    } else if (READ_FLAG(UC0IFG, UCB0RXIFG))
+    } else if (READ_FLAG(UC0IFG & UC0IE, UCB0RXIE)) {
       signal IntB.rx(UCB0RXBUF); /* read clears UCB0RXIFG */
-    else if (READ_FLAG(UCB0STAT, 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(UCB0STAT, UCALIFG)) {
+      CLR_FLAG(UCB0STAT, UCALIFG);
       signal IntB.i2cCal();
-    else if (READ_FLAG(UCB0STAT, UCNACKIFG))
+    } else if (READ_FLAG(UCB0STAT, UCNACKIFG)) {
+      CLR_FLAG(UCB0STAT, UCNACKIFG);
+      CLR_FLAG(UC0IFG, UCB0TXIFG); /* Errata USCI25; 'reset' means clear? */
       signal IntB.i2cNak();
-    else if (READ_FLAG(UCB0STAT, UCSTTIFG))
+    } else if (READ_FLAG(UCB0STAT, UCSTTIFG)) {
+      CLR_FLAG(UCB0STAT, UCSTTIFG);
       signal IntB.i2cStart();
-    else if (READ_FLAG(UCB0STAT, UCSTPIFG))
+    } else if (READ_FLAG(UCB0STAT, UCSTPIFG)) {
+      CLR_FLAG(UCB0STAT, 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_A0 can receive events
+   * for UART and SPI modes, while USCI_B0 can receive events for I2C and SPI
+   * modes.
    */
   TOSH_SIGNAL(USCIAB0TX_VECTOR) {
-    if (READ_FLAG(UC0IFG, UCB0RXIFG))
+    if (READ_FLAG(UC0IFG & UC0IE, UCB0RXIE))
       signal IntB.rx(UCB0RXBUF); /* I2C receive */
-    else if (READ_FLAG(UC0IFG, UCA0TXIFG))
+    else if (READ_FLAG(UC0IFG & UC0IE, UCA0TXIFG))
       signal IntA.tx();
-    else if (READ_FLAG(UC0IFG, UCB0TXIFG))
+    else if (READ_FLAG(UC0IFG & UC0IE, UCB0TXIFG))
       signal IntB.tx();
   }
 
@@ -108,6 +123,7 @@ implementation
   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() {}