Index: firmware/drivers/rtc/rtc_as3514.c
===================================================================
--- firmware/drivers/rtc/rtc_as3514.c	(revision 27293)
+++ firmware/drivers/rtc/rtc_as3514.c	(working copy)
@@ -68,8 +68,36 @@
     *m = wakeup_m;
 }
 
+/* Reads the AS3543 wakeup register */
+static void wakeup_read(unsigned char *buf, int len)
+{
+    int i, oldstatus;
+
+    oldstatus = disable_irq_save();
+    ascodec_read(0);
+    for (i = 0; i < len; i++) {
+        buf[i] = ascodec_read(AS3543_WAKEUP);
+    }
+    restore_irq(oldstatus);
+}
+
+/* Writes the AS3543 wakeup register */
+static void wakeup_write(unsigned char *buf, int len)
+{
+    int i, oldstatus;
+    
+    oldstatus = disable_irq_save();
+    ascodec_read(0);
+    for (i = 0; i < len; i++) {
+        ascodec_write(AS3543_WAKEUP, buf[i]);
+    }
+    restore_irq(oldstatus);
+}
+
 void rtc_alarm_poweroff(void)
 {
+    unsigned char buf[6];
+
     if(!alarm_enabled)
         return;
 
@@ -91,26 +119,19 @@
 
     seconds -= tm.tm_sec;
 
-    disable_irq();
+    /* write wakeup register */
+    buf[0] = seconds  & 0xFF;
+    buf[1] = (seconds >> 8) & 0xFF;
+    buf[2] = ((seconds >> 16) & 0xFF) | (1 << 7);
+    buf[3] = 0x80;      /* prevents OF database refresh from micro SD */
+    buf[4] = wakeup_h;
+    buf[5] = wakeup_m;
+    wakeup_write(buf, sizeof(buf));
 
-    ascodec_write(AS3543_WAKEUP, seconds);
-    seconds >>= 8;
-    ascodec_write(AS3543_WAKEUP, seconds);
-    seconds >>= 8;
-    seconds |= 1<<7; /* enable bit */
-    ascodec_write(AS3543_WAKEUP, seconds);
-    
-    /* write 0x80 to prevent the OF refreshing its database from the microSD */
-    ascodec_write(AS3543_WAKEUP, 0x80);
-
-    /* write our desired time of wake up to detect power-up from RTC */
-    ascodec_write(AS3543_WAKEUP, wakeup_h);
-    ascodec_write(AS3543_WAKEUP, wakeup_m);
-
-    /* enable hearbeat watchdog */
+    /* enable heartbeat watchdog */
     ascodec_write(AS3514_SYSTEM, (1<<3) | (1<<0));
 
-    /* In_Cntr : disable hearbeat source */
+    /* In_Cntr : disable heartbeat source */
     ascodec_write_pmu(0x1a, 4, ascodec_read_pmu(0x1a, 4) & ~(3<<2));
 
     while(1);
@@ -123,20 +144,22 @@
 
 bool rtc_check_alarm_started(bool release_alarm)
 {
+    unsigned char buf[6];
+
     (void) release_alarm;
 
-    /* 3 first reads give the 23 bits counter and enable bit */
-    ascodec_read(AS3543_WAKEUP); /* bits  7:0  */
-    ascodec_read(AS3543_WAKEUP); /* bits 15:8  */
-    if(!(ascodec_read(AS3543_WAKEUP) & (1<<7))) /* enable bit */
+    /* read wakeup register and check if alarm was enabled */
+    wakeup_read(buf, sizeof(buf));
+    if (!(buf[2] & (1 << 7))) {
         return false;
-        
-    /* skip WAKEUP[3] which the OF uses for other purposes */
-    ascodec_read(AS3543_WAKEUP);
+    }
+    wakeup_h = buf[4];
+    wakeup_m = buf[5];
 
-    /* subsequent reads give the 16 bytes static SRAM */
-    wakeup_h = ascodec_read(AS3543_WAKEUP);
-    wakeup_m = ascodec_read(AS3543_WAKEUP);
+    if (release_alarm) {
+        buf[2] &= ~(1 << 7);
+        wakeup_write(buf, 3);
+    }
 
     struct tm tm;
     rtc_read_datetime(&tm);