PCMCIA 16 bit Bus

PC Card
Personal Computer Memory Card International Association

[PC Card Description] [Interface ICs]
[PC Card Standard Organizations]
[Pin-Out] [PCMCIA Connectors]
[PCMCIA Cards]


PC Card Description

The PCMCIA [PC Card] specification defines both the Electrical and Physical specifications for a 68 pin interface residing in one of 3 form factors, which differ only in thickness;
Type I: dimensions 3.3mm x 85.6mm x 54.0mm (TxLxW), Version 2.1 allows the length to increase 50mm to 135mm
Type II: dimensions 5.0mm x 85.6mm x 54.0mm (TxLxW), Version 2.1 allows the length to increase 50mm to 135mm
Type III: dimensions 10.5mm x 85.6mm x 54.0mm (Tall x Length x Width)

In most cases cards designed to the PCMCIA specification are used on laptop computers. The smaller size of the PCMCIA card can be used to implement normal desktop expansion boards into a smaller form factor which may be inserted into a notebook computer. PCMCIA cards are commonly used as memory expansion [physical memory, or hard disk drive], modem, or other uses. In some case PCMCIA slots are also provided on desk top computers.

The implementation of this spec based on the ISA bus is termed the PC Card with a 8/16 bit data bus, 26 address lines, and no bus mastering. PC Card-16 cards use an 8-bit or 16-bit interface that operates at ISA bus speeds (10 MHz) using an ISA-like asynchronous protocol. It's called CardBus when implementing the local PCI bus (32 data bits only). All of the PCMCIA implementations use Plug and Play and have Hot Swapping capabilities. The 16-bit PCMCIA 'PC Card' will operate up to a maximum of 20MBps, or 160Mbps. However the actual throughput will depend on the minimum cycle time and the transfer mode [Byte/Word] and will never reach the maximum throughput rates.

Miniature Card is a smaller implementation of PCMCIA. Miniature Cards dimensions 3.5mm x 33mm x 38mm (Tall x Length x Width). The electrical specifications are a subset of the PC Card standard, restricted to memory applications only. It uses a 16-bit data bus and a 24-bit address bus to allow a single card to store up to 64MB.

The PCMCIA 'PC Card' standard [discussed on this page] should not be used as an up-grade because it's based on the slower ISA bus standard. Use the Cardbus standard of PCMCIA instead, which is based on the PCI bus specification. The PCI implementation in Cardbus is much faster, and a newer bus standard. I've heard that version 2 [1991] of the PCMCIA standard was not widely followed or was not well defined. Version 2.1 [1993] addressed some of the standards issues, but may still have issues with standardization. The PCMCIA 'PC Card' bus is obsolete, and should not be used for new designs. At a minimum use the PCI version of the bus discussed above. Removable memory cards are produced in a number of different formats

Comparison of Removable Memory Card Dimensions

The figure provides a comparison of different types of flash memory cards and the PC Card format.
For additional information on other flash memory board standards refer to the Personal Computer Buses page.

{PC Card Index}

PCMCIA Standard Organizations

The PC Card specification was released in 1990, version 2.0 in 1991, version 2.1 in 1993, version 5.0 in 1995, version 8.0 released in 2001

Personal Computer Memory Card International Association

{PC Card Index}

PCMCIA Bus Interface ICs

No IC manufacturers are listed because this interface is out-dated.
The PC Card standard has been replaced by the CardBus standard, and ExpressCard standard.
Use the link below to search for IC manufacturers.

IC Manufacturers {All other types}

{PCMCIA PC-Card Index}

PCMCIA Connector Manufacturers

The PC Card uses a 68 pin connector, with two rows of 34 pins, with 0.05 inch spacing [1.27mm]. Female pins are used on the card side, male pins on the system end.
The power and ground pins are longer than the signal lines, allowing them to make connect first.

Physical Dimensions of the PC Card Connector, Molex

AVX {PCMCIA PC Memory Card Connector, PCMCIA Frameless Kit}
Foxconn Electronics {PCMCIA Card End Connector, SMT Type, Pitch 1.27mm [.050"], 68 Pos.}
Molex Inc. {PCMCIA Connectors}
OUPIIN America Inc. {Through-Hole PCMCIA Socket, 34 contact per row, x2}

{PC Card Index}

PC Card, Pin Out

The table provides the pin out for the 16-bit PC Card.

PCMCIA 68-pin Connector Pin Out And Signal Names
Pin # Signal Name Pin # Signal Name Pin # Signal Name Pin # Signal Name Pin # Signal Name
1 Ground 15 WE 29 A0 43 VS1/RFSH 57 VS2/RFU
2 D3 16 Ready 30 D0 44 Reserved 58 Reset
3 D4 17 Vcc 31 D1 45 Reserved 59 Wait
4 D5 18 Vpp1 32 D2 46 A17 60 Reserved
5 D6 19 A16 33 Wp 47 A18 61 Reg
6 D7 20 A15 34 GND 48 A19 62 BVD2
7 CE1 21 A12 35 GND 49 A20 63 BVD1
8 A10 22 A7 36 CD1 50 A21 64 D8
9 OE 23 A6 37 D11 51 Vcc 65 D9
10 A11 24 A5 38 D12 52 Vpp2 66 D10
11 A9 25 A4 39 D13 53 A22 67 CD2
12 A8 26 A3 40 D14 54 A23 68 GND
13 A13 27 A2 41 D15 55 A24 -- ---
14 A14 28 A1 42 CE2 56 A25 -- ---

PCMCIA Extender Cables;

PCMCIA Modules; PCMCIA Card Manufacturers

{PCMCIA PC Card Index}

PC motherboard

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Modified 3/04/12
Copyright © 1998 - 2012 All rights reserved Leroy Davis