CYGNUM_HAL_RTC_CONSTANTS

I think you're right. It looks like these constants are back to front. I believe that what's given below is more correct (although I'll need to do some further testing to be sure):

/*
 * Construct some intermediate defines that are used to extract the timer 
 * configuration from the auto-generated system.h header file.
 */
# define ALT_AVALON_TIMER_PERIOD_UNITS_S      0# define ALT_AVALON_TIMER_PERIOD_UNITS_MS     1# define ALT_AVALON_TIMER_PERIOD_UNITS_US     2# define ALT_AVALON_TIMER_PERIOD_UNITS_CLOCKS 3
# define __ALT_CLK_BASE(name) name##_BASE# define _ALT_CLK_BASE(name) __ALT_CLK_BASE(name)# define ALT_SYS_CLK_BASE _ALT_CLK_BASE(CYGHWR_HAL_SYSCLK_DEV)
# define __ALT_CLK_IRQ(name) name##_IRQ# define _ALT_CLK_IRQ(name) __ALT_CLK_IRQ(name)# define ALT_SYS_CLK_IRQ _ALT_CLK_IRQ(CYGHWR_HAL_SYSCLK_DEV)
# define __ALT_CLK_PERIOD(name) name##_PERIOD# define _ALT_CLK_PERIOD(name) __ALT_CLK_PERIOD(name)# define ALT_SYS_CLK_PERIOD _ALT_CLK_PERIOD(CYGHWR_HAL_SYSCLK_DEV)
# define __ALT_CLK_PERIOD_UNITS(name) name##_ALT_AVALON_TIMER_PERIOD_UNITS# define _ALT_CLK_PERIOD_UNITS(name) __ALT_CLK_PERIOD_UNITS(name)# define ALT_SYS_CLK_PERIOD_UNITS _ALT_CLK_PERIOD_UNITS(CYGHWR_HAL_SYSCLK_DEV)
# define __ALT_CLK_FREQ(name) name##_FREQ# define _ALT_CLK_FREQ(name) __ALT_CLK_FREQ(name)# define ALT_SYS_CLK_FREQ _ALT_CLK_FREQ(CYGHWR_HAL_SYSCLK_DEV)
/*
 * Having extracted the timer constants, use these to contruct the real time clock constants
 * required for eCos.
 */
# define CYGNUM_HAL_RTC_CONSTANTS (1)
# define CYGNUM_HAL_RTC_NUMERATOR (1000000 *  ALT_SYS_CLK_PERIOD * 
           ((ALT_SYS_CLK_PERIOD_UNITS == ALT_AVALON_TIMER_PERIOD_UNITS_S ) ? 1000 : 1))# define CYGNUM_HAL_RTC_DENOMINATOR ((ALT_SYS_CLK_PERIOD_UNITS == ALT_AVALON_TIMER_PERIOD_UNITS_US ) ? 1000 : 
                                     (ALT_SYS_CLK_PERIOD_UNITS == ALT_AVALON_TIMER_PERIOD_UNITS_CLOCKS ) ?   
         (ALT_SYS_CLK_FREQ/1000) : 1)# define CYGNUM_HAL_RTC_PERIOD (ALT_SYS_CLK_FREQ / CYGNUM_HAL_RTC_DENOMINATOR / 
                                     ((ALT_SYS_CLK_PERIOD_UNITS != ALT_AVALON_TIMER_PERIOD_UNITS_S ) ? 1000 : 1))
# define CYGNUM_HAL_INTERRUPT_RTC ALT_SYS_CLK_IRQ