Index: kernel/arch/arm32/src/mach/gta02/gta02.c
===================================================================
--- kernel/arch/arm32/src/mach/gta02/gta02.c	(revision dfd735a17f05114b7c3cfafef153c4894f4737cb)
+++ kernel/arch/arm32/src/mach/gta02/gta02.c	(revision 24697c38d07549b7e4f28de6c2554f03604f037f)
@@ -225,6 +225,15 @@
 	 */
 
-	/* Set prescaler values to zero. (no pre-divison), no dead zone. */
-	pio_write_32(&timer->tcfg0, 0);
+	/*
+	 * GTA02 PCLK should be 100 MHz.
+	 * Timer input freq. = PCLK / divider / (1+prescaler)
+	 * 100 MHz / 2 / (1+7) / 62500 ~= 100 Hz
+	 */
+#if HZ != 100
+#warning Other HZ than 100 not suppored.
+#endif
+
+	/* Set prescaler values. No pre-divison, no dead zone. */
+	pio_write_32(&timer->tcfg0, 7); /* prescale 1/8 */
 
 	/* No DMA request, divider value = 2 for all timers. */
@@ -235,5 +244,5 @@
 
 	/* Start counting from 64k-1. Compare value is irrelevant. */
-	pio_write_32(&timer->timer[0].cntb, 0xffff);
+	pio_write_32(&timer->timer[0].cntb, 62500);
 	pio_write_32(&timer->timer[0].cmpb, 0);