PCI-Express0 pages
PCI-EXPRESS
Single-slot 32 bit PCI Express module
IRIG A, B, NASA 36, 1 PPS sync inputs
GPS sync option (maintains single-slot)
HaveQuick sync input option
Propagation delay correction
Zero latency time reads
Match Time output
IRIG-B time code output (option)
External Event time tags
Three user programmable rates
The PCI-Express from Brandywine Communications provides
precision time with zero latency to the host computer through
a PCI Express X1,X2,X4,X8,X16 or X32 slot. 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.
Internal or external processes may be automatically initiated
or terminated by using the Match Time feature. This feature
asserts an output when the clock's time matches that of the
user input start time. The output is terminated under user
control or when the pre-programmed stop time is encountered. The resolution of the Match Time comparison is one
microsecond.
Three user programmable pulse rates are provided. Two
pulse rates, Clock Low and Clock High, are available on the
multi-pin connector. The third rate generator provides heartbeat timing to the host. The divider for each of the three rate
generators is programmable by the host over the range 2–
65,535. The inputs to the rate generators are 3 MHz or 100
Hz for the heartbeat, 3 MHz for Clock High and 100 Hz for
Clock Low.
The GPS synchronization option adds worldwide time transfer
capability that can be traced to the U.S. Government standard
UTC-USNO. Very precise synchronization, automatic leap
year and leap second correction, and accurate position information are additional benefits provided by the GPS option.
Software packages for Windows, VxWorks and Linux are
available. C language samples are supplied with the PCIExpress.
In addition to the comprehensive set of standard capabilities
of the PCI-Express, Brandywine Communications offers a
wide range of options that may be specified. These options
allow the user to customize the PCI-Express to fit almost any
application.
1153 Warner Ave ● Tustin, CA 92780 ● 714-755-1050 phone ● 714-755-0175 fax
info@brandywinecomm.com
www.brandywinecomm.com