Simplex G-Link Test Source Card
This Data Sheet describes a test data generator card which uses the HP
G-Link as its physical medium.
This card is using the same hardware as the simplex G-Link-S-LINK LSC,
it differs from it in the FPGA configuration. Data is generated in an FPGA
which is clocked with a 40 Mhz quartz oscillator. Parallel data is sent
to the HDMP-1022 serialiser which transmits the serial data to the media
interface. The media interface can be a laser transmitter or a coaxial
20 bit and Single Frame G-LINK mode is used
Data Transfer Rate
The parallel data rate is 40 Mhz. This corresponds to 960 Mbaud serial
data rate since the G-Link sends 24 bit data with each 20 bit data word.
Flow control is not available.
The card transmits data in packets which consist of a start of packet control
word, 224 data words and an end of packet control word. Fill Frames are
transmitted between the packets. Test data is transmitted on the 16 LSB
of the data words. Bits 19-16 contain the odd parity of each four bits
of the 16 LSB and can be used for error detection. E.g. bit 20 is the odd
parity of bits 15-12.
Four different data patterns can be selected with the P1, P0 input
signals (see Table 1). A reset input signal is available to force
the transmitter to send Fill Frames. It can be used for receiver synchronisation.
These inputs are either TTL signals, on board switches or differential
(RS-422) signals depending on the actual card configuration.
Table 1: Output Selection
||Link Up Led
Power Led (green): It turns on when the card is powered with 5 V.
Link Up Led (green): This led turns on after the PLL of the G-Link
serialiser is synchronised, normally less than 1ms after the power is turned
on or the Reset input is pulled low. This led is off when the reset input
is logic high.
Simplex G-Link Test Source
Last Updated: 25.06.1999 by Zoltán