Spectracom TPRO-cPCI, User Manual, Page: 27 / 46

Spectracom Corporation TPRO-cPCI/TSAT-cPCI
Synchronizable Timecode Generator User Manual 4-5
4.3.9.9 Interrupt Enables
These six bits are asserted or de-asserted by writing to the corresponding bits in the Interrupt
Enable Register. The user can read-back these bits by reading the Status Register. Writing "1"
enables the interrupt. The power-on default is "0".
The interrupt will be asserted as long as the Interrupt Enable and Flag bits are both "1". Be sure
that the corresponding flag bit is not asserted before setting the Interrupt Enable bit; otherwise,
an unexpected interrupt will occur. The user's interrupt handler software acknowledges the
interrupt by clearing the corresponding flag bit.
4.3.9.10 IRQ Enable–Match
This bit enables an interrupt when Flag–Match is asserted.
4.3.9.11 IRQ Enable–Heartbeat
This bit enables an interrupt when Flag–Heartbeat is asserted.
4.3.9.12 IRQ Enable–Time Tag
This bit enables an interrupt when Flag–Time Tag is asserted.
4.3.9.13 IRQ Enable–Command Complete
This bit enables an interrupt when Flag–Command Complete is asserted.
NOTE: Use this interrupt carefully. The only way to clear Flag-Command Complete is to send
another command. This interrupt might be useful if a series of commands is to be
sent, but most applications will not use this feature.
4.3.9.14 IRQ Enable–Sync Change
This bit enables an interrupt when Flag–Sync Change is asserted. This is useful for determining
that synchronization has been established or lost.
4.3.9.15 Enable/Disable Time Tag Input
This bit enables (1) or disables (0) the Time Tag Input on the TIMING connector. Write "1" or
"0" to the corresponding bit in the Interrupt Enable Register. The
user can read-back this bit by
reading the Status Register. The power-on default is "0" (disabled).
4.3.9.16 Synchronization Source Indicator
These three bits indicate which input time source is being used. This is intended for diagnostic
purposes only.
tbstat_ssi[2:0] Input Time Source
000 Searching for time code input (TPRO-cPCI)
Acquiring GPS satellites (TSAT-cPCI)
001 Time Code Input (IRIG-A autodetected)
010 Time Code Input (IRIG-B autodetected)
011 Time Code Input (NASA36 autodetected)
100 GPS Satellites
Others (reserved for future use)