VME P2 Connector Pin-Out

The table below defines the pin out for the VME P2 connector. The table which defines the pin-out for the VME P1 connector is listed on the VMEbus P1 pin out page. Both Pin-Out tables define the 96 Pin DIN Connectors: 3 Rows x 32 Pins. Links to the 5-row [VME64] pin out are listed after the table. The main VMEbus page provides additional details including a bus interface description, Timing, connector types, card sizes, and electronic equipment and component manufacturers.

Pin # Signal name Signal name Signal name
  Row A Row B Row C
1 User Defined +5v User Defined
4 A24
5 A25
6 A26
7 A27
8 A28
9 A29
10 A30
11 A31
12 GND
13 +5v
14 D16
15 D17
16 D18
17 D19
18 D20
19 D21
20 D22
21 D23
22 GND
23 D24
24 D25
25 D26
26 D27
27 D28
28 D29
29 D30
30 D31
31 GND
32 +5V

The VME bus interface I/O types are listed below:
Open collector signals which require Open Collector drivers and receivers:
Three-State signals which require 3-State drivers and receivers:
AS, DS0, DS1, DTACK, RETRY, IACK, LWORD, WRITE, [AM0 - AM5], [A01 - A31], and [D00 - D31].
Totem-Pole signals which require Totem-Pole drivers and receivers:

The pin-out for the VME P2 connector is listed above. All cards most have a P1 connector, which normally defines a 3U high card. Boards which have a P2 are 6U boards (double height). How ever 6U circuit cards are produced which do not have a P2 connector, or a card may have a P2 but may not bus the "B" row.
The P1 connector provides all the bus control signals for a 16 bit data bus and a 24 bit address bus. Using the P2 connector allows the card to use a 32 bit address bus, and a 32 bit data bus. The 32 bit data bus may be increased to 64 bits during BLock Transfers if the upper 32 bits of data are multiplexed onto the address bus.

The P2 connector also provides 2 rows of 32 pins (64 pins) on rows "A" and "C" (labeled "N/C" above) as user defined pins. These pins are not bused on the back plane and may be used by the board for any reason. Of coarse, all boards use them to increase their I/O.
Some boards adopt the "user defined" pins of rows A and C in a unique fashion, so the signals coming out will only support their card. Other cards will follow an IEEE or VITA standard to support their I/O, and still others don't require the additional I/O and don't bus the signals at all. Many cards use the pins to communicate with "Transition" cards which either reside in the rear of the chassis or the rear of the back-plane. For the cards which bus their signals as defined by a specification, their are a number of them, a short list is provided (with details, on either the "Mezzanine Bus" page or the "VME (P2) Add on Buses" page.

When the board uses a daughter card it may follow one of the Mezzanine standards to bring out its I/O. The IP standard is normally used to produce more (varied) I/O, or the PMC standard may be used (which provides more processing power).
Boards may be produced which allow one of a number of high speed "Cross-Bar" switches to increase the through-put of VME cards on the bus. RaceWay does this by adding a daughter card (on the rear of the back plane) across the P2 connectors.
A number of card designs place serial buses onto the user defined P2 pins, these include: Autobahn, and SkyChannel.

VME64x and VME64 (optional) come with an enhanced connector. Five rows instead of the 3 rows used in the original VME specification. The 160 pin DIN (5 row x 32 pin) add rows "z" and "d". Primarily these additions are power (+3.3 volts) and ground (GND) on P1 and 'User Defined' on P2 (next page). Rows "A", "B", and "C" remain unchanged. The VME64 five row connector pinout is depicted on either the VMEbus P1 Pin out page or VMEbus P2 Pin out page.

There are a number of different connector types used with the VMEbus
P1 and P2 are 96 pin DIN (41612, Type C) 3 rows x 32 pins [Pitch 2.54mm (.100")] @ IEEE 1014-1987; [VME]
P1 and P2 are 160 pin DIN (41612, Type C Expanded) 5 rows x 32 pins [Pitch 2.54mm (.100")] @ ANSI/VITA 1-1994; [VME64]
P1 connectors may also come with an Auto Bus Grant [ABG] option which is an automatic [mechanical] switching capability built-in to auto jumper the slot

P2 Split DIN / RF Coax (DIN 41612 Type M) DIN + Coax @ 78 + 2, 60 + 4, 42 + 6, 24 + 8

The class of connectors determines the number of insertions it's [Mechanical Endurance] designed to handle per DIN 41612.
Class 1: 500 mating cycles [the highest grade connector]
Class 2: 400 mating cycles [mid-grade]
Class 3: 50 mating cycles [the lowest grade]

A listing of companies that manufacturer VME DIN connectors and electronic equipment and component manufacturers
is listed on the main VMEbus page with additional details including connector types, bus pin outs.

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference

Modified 12/31/11
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