Simplex G-Link Receiver Card Data Sheet
This Data Sheet describes a Simplex Destination card which
uses the HP G-Link HDMP-1024 receiver and optical or electrical physical
media. This card is equipped with an S-LINK interface and data can
be read with any S-Link read-out system.
Data Transfer Rate
The maximum clock rate (LCLK) is 40 Mhz. Minimum frequency of LCLK is 17.5
Mhz in 16 bit G-Link mode and 29.2 Mhz in 20 bit G-Link mode. 32 words
at 40 Mwords/sec (40Mhz LCLK) is above the specified data rate for G-Link
so not guaranteed but is inside the typical maximum data rate. Maximum
guaranteed data rate is 37.5 Mword/sec in 32 bit mode.
Since it is a simplex link, flow control is not available. The Uxoff#
input is reserved.
The "TP2" 20 bit mode selector jumper must be on the card when the transmitter
is in 20 bit mode.
4 jumpers can be used to select different operation modes. Flag mode
and 20 bit G-Link mode selection must be the same on both source and destination
Table 1: S-LINK operation modes
|Serial Baud Rate at 40Mhz LCLK
||Coding + Flag + Parity
||Coding + Flag
Table 2: Operation Modes
||Flag bit mode: Flag bit can be used as an extra dataword.
||Flag bit is is internally alternated by G-Link for enhanced error detection.
||20 bit G-Link mode
||16 bit G-Link mode
||Link Synchronisation with on-board reference oscillator
||Link Synchronisation with sync. pulses (Fill Frames)
Optical Power and Board Temperature
It is possible to measure received optical power and the temperature of
the circuit board next to the G-Link deserialiser (HDMP-1024). On a high-low
transition of the UTDO# (S-LINK) input a control word is sent whith optical
power and temperature measurement results. Optical power in dBm is -0.1
times the decimal value on bits 23-16. E.g. the binary "01000001" value
means -6.5dBm. Temperature can be read on bits 15-6 with 0.25 degrees accuracy
E.g. "0011000110" means 49.5 °C. UTDO must be pulled high
to receive G-Link data.
The 16 MSB of the S-LINK data output are used for error checking
and diagnostic purposes. Table 4 shows the allocation of LD[31..0] bits.
The "#" symbol means an active low signal.
|CAV# (Control Word)
||DAV# (Data Word)
||ERR (G-Link error)
||FLAG (G-Link Flag)
||Free running counter
Table 3: Output Data bits
||Rx Data (Parity)
Word by word error reporting is possible using the "Error" signal of
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
deserialiser is synchronised.
Data Error led (red): This Led turns on when G-Link Error.
It turns off on the high to low transition of URESET# input.
Selftest Led (red): This led is illuminated when UTD0# is low.
When UTDO# is pulled low, the optical power of the received light and the
temperature on board next to the serialiser is sent to the user in a control
Last Updated on 30.06.1999 by Zoltán