BC635VME TIME AND FREQUENCY PROCESSOR
- The Time and Frequency Processor (TFP) has been designed with the following key features:
-
- Time on demand (days through 0.1 microseconds) with zero latency. This feature is implemented with hardware registers which latch the current time upon host request.
- Event logging (days through 0.1 microseconds). This feature is implemented with a second set of hardware registers. Time is captured on a positive or negative input edge.
- Six operational modes are supported. Modes are distinguished by the reference source.
Mode |
Source Of Synchronization |
0 |
Timecode – IRIGA IRIGB XR3 2137 NASA36 |
|
1 |
Free running – on board VCXO used as reference. |
|
2 |
1 pps – accepts input one pulse per second. |
|
3
|
RTC – uses battery backed on board real time clock IC.
|
|
5 |
GPS (optional) – double wide configuration including GPS receiver. (obsolete) |
|
6
|
GPS (optional) – uses GPS receiver/antenna (receiver in antenna).
|
Datum Inc bc635VME/bc350VXI Time and Frequency Processor (Rev. D) 1-1
CHAPTER ONE
- Provides an output clock synchronized to the selected reference; programmable 1, 5, or 10MHz TTL.
- All modes of operation are supplemented by flywheel operation. For example, if synchronization source is lost, the TFP will continue to function at the last known reference rate.
- Generates synchronized IRIG B timecode. Modulated and DC level shift formats are produced simultaneously. Also generates IRIG H DC level shift.
- Programmable frequency output (periodics) is provided. The output frequency is 10,000,000 / (n1 * n2). 1<n1<65536 & 1<n2<65536.
- A time coincidence strobe output is provided. Programmable from hours through milliseconds. This strobe also has an each second mode programmable to milliseconds.
- Five maskable interrupt sources are supported. IRQ levels one through seven are programmable.
|
Int. # |
Source Of Interrupt |
|
0 |
External event input has occurred. |
|
1 |
Periodic output has occurred. |
|
2 |
Time coincidence strobe has occurred. |
|
3
|
One second epoch (1pps output) has occurred.
|
|
4
|
Output data packet is available.
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- Time-of-day, hours, minutes, and seconds are displayed on front panel LED’s.
- Most inputs and outputs are accessible via the P2 connector.