Chapter 2 Installation 232.16 VGA interface connectionsThe PCM-5820/5820L board's SVGA interface can facilitatesconventional CRT displays as well as active LCD displays. Thecard has two connectors to support these displays, one for standardCRT VGA monitors and one for flat panel displays.2.16.1 CRT display connector (CN18)CN18 is a 15-pin, D-SUB connector commonly used for conven-tional CRT displays.Detailed information on pin assignments for CRT display connec-tor CN18 is given in Appendix A.2.16.2 Flat panel display connector (CN12)CN12 consists of a 44-pin, dual-in-line header.The power supply (+12 V) for CN12 is dependant on the supplyconnected to the board. Therefore ensure that CN9 is connected toa +12 V power supply.The PCM-5820/5820L provides a bias control signal on CN12which can be used to control the LCD bias voltage. It is recom-mended that the LCD bias voltage not be applied to the panel untilthe logic supply voltage (+5 V or +3.3 V) and panel video signalsare stable. Under normal operation the control signal (ENAVEE) isactive high. When the PCM-5820/5820L board's power is applied,the control signal is low until just after the relevant flat panelsignals are present.2.16.3 LCD power setting (J6)The PCM-5820/5820L’s PCI SVGA interface supports 5 V and 3.3V LCD displays. By changing the setting of J6, you can select thepanel video signal level to be 5 V or 3.3 V.
