The PCI-Express time code reference timing card with standard options such as IRIG B and optional GPS receiver provides an extremely accurate time source to the PCI-Express bus. This syncclock acts as a time code reader and/or time code generator that is synchronized to an external source of time such as IRIG B, IRIG A, IRIG G, NASA36 or Have Quick Time Code. An optional on-board GPS receiver allows another source of synchronization.

The PCI Express card uses its time source to generate time from an internal disciplined oscillator, that can be accessed across the PCI-Express bus through a set of zero latency time registers. Time synchronization can be achieved by simply reading the time registers, using this PCI card to generate periodic interrupts, or the PCI-Express can latch the time of an external event.

The PCI-Express card is the newest member to Brandywine’s bus level family of timing cards and is quickly becoming one of the most used PCI cards, replacing its older counterparts.

The PCI-Express from Brandywine Communications provides precision time with zero latency to the host computer over the PCI bus. An on-board microprocessor automatically synchronizes the clock to reference signal inputs. The reference signal inputs can be 1 PPS, IRIG or NASA time codes and optionally, GPS or HaveQuick. The clock can free run and be set by commands from the host over the PCI Express bus.

The on-board clock accepts an IRIG A, B, or NASA 36 input and accepts user input reference input signal delay information. An IRIG B code generator is available.

The advanced microprocessor on the PCI-Express module constantly measures the time error between the on-board clock and the reference input code and adjusts the error measurement for propagation delay. In units with a disciplined TCXO or OCXO the residual error is used in an adaptive gain loop to adjust the frequency of the oscillator for minimum error. If the incoming time code is missing, or corrupted by noise, the on-board clock is updated using the disciplined oscillator. When the input code is again useable the correction loop is smoothly closed.

58 bits of BCD time data are available to the host computer using two zero latency time reads. The time message contains units of microseconds through units of years. A status word is available using an additional read.

The exact time-of-occurrence of random external events may be captured by using the Event Time input. When the event input is sensed the current time is saved in a buffer for later interrogation by the host. The resolution of the time tag is 100 nanoseconds.