Application Notes Application otes VME64x Applications The IEEE 1101.10 Standard employs the same 19-position 2mm family of connectors as is used in VME64x applications. This center connector, located in slot JO/PO for VME64x backplane layouts shown below in figure 2 reveals pinout assignments with Row/Position A1 located at the top slot 1 edge of the pinfield. The depictions below describe the front and rear views respectively, and the corresponding A1 Location. This clarification is needed to properly identify where A1 is located with respect to the cable assembly and application being employed. Note that the latches, which ruggedize the interface, are depicted on the left side of the shroud when viewing the slots from the rear. These Application Notes are intended to explain differences in numbering schemes commonly used with the extended 2mm HM series for I/O applications. The importance of these differences is to qualify the wiring issues surrounding single-ended and double-ended assemblies, as well as single- ended applications requiring labels on the unterminated end. The figures 1 and 2 on pages 13 and 14 clearly present the differences existing between the two standards that currently employ the 2mm HM connector system. Figure 2 - VME64x Backplane Layout 19 1 ZABCDEF 19 1 ZABCDEF 19 1 ZABCDEF 19 1 FEDCBAZ 19 1 FEDCBAZ FEDCBAZ FEDCBAZ 19 1 ZABCDEF 1.85 18 20 22 24 26 28 30 32 18 20 22 24 26 28 30 32 a1 2 4 6 8 10 12 14 a1 2 4 6 8 10 12 14 Front View Rear View Figure 2 Shroud Orientation When shrouds are used on the rear of the backplane, care must be taken to align the shrouds properly. The correct orientation will depend upon the configuration of the rear plug-in cards. For most applications following the “inline” configuration, the rear shrouds will have the convex and detail facing down as depicted in the circle in Figure 3. The “a” row of the shroud will match the “a” row of the male connector. This preferred orientation of the shroud will enable the cable system to be securely latched on the left side when viewing from the rear of the backplane, as shown in Figures 1 and 2. Figure 3 PICMG 2.1 R3.0 specifies an AB19 shroud for rear plug in applications (rP3/rJ3). However, cable assemblies used for I/O routing currently require a B19 shroud. HPM seri es 2 mm advantage MERITEC 888-MERITEC (888-637-4832) / (440)-354-3148 FAX: (440) 354-5692 www.meritec.com info@meritec.com Page 1 5 2mm HM header w/ feed through pins VME 64X backplane ERNI Shroud Front Rear ERNI latch arm 064219 Latch View (side) Facing Row F position 1 through 19 top to bottom 888 -MERITEC ( 637- 4832 ) HPM Series 2-mm Advantage High - Per formance Metric 15 www.meritec.com