USING ISA & PCMCIA CARDS OUTSIDE THE BOX

USING ISA & PCMCIA CARDS OUTSIDE THE BOX

Servicing Multiple ISA Cards and PCMCIA Cards with Our USB to ISA and USB to PCMCIA Families of Cards

1. Background



The purpose of this article is to propose a change of the architecture, in servicing of ISA and PCMCIA cards. It brings examples of the current ways of servicing of these types of cards, and examples of replacements and new architectures.

Since the products we offer are based on USB, the rest of the chapter will give details on the USB interface and our products.

The existing USB interface allows servicing of up to 128 USB devices.

These devices are connected normally with USB cable which can be from 1 foot to 15 feet (30cm to 5m) long.

Our current USB devices product offerings include -

- USB to PCMCIA card - allows use and handling of one PCMCIA card

- USB to ISA family, which includes -

  • USB to ISA card - allows use and handling of one ISA card
  • USB to ISA slot version card - handles several ISA cards mounted on a passive ISA back plane
  • USB to ISA 3 connector card - handles up to 3 ISA cards
  • USB to ISA 7 connector card - handles up to 7 ISA cards

    The current software implementation for the USBISA family allows control of up to 7 devices. This means for example control of up to 7 ISA cards mounted on USBISA-x7 type cards.

    Each individual USBISA type card, or USBPCMCIA controls separate resources, each one has a separate from other cards - memory space, i/o space , IRQ channels , and DMA channels .

    2. Current ways of using ISA cards

    The example bellow shows 3 separate computer systems. These systems may be in the form of desktop computers or industrial computers and may run a general desktop operating system or an embedded operating system.

    These computers may be connected in a network to exchange their data, or they may be stand alone.

    In addition to the assigned functions to these computer systems, they have to service the ISA cards present into them. In the example, three types of ISA cards with one or two of them in each computer system.

    more isa 1

    3. Examples of new architectures for servicing of ISA cards –

    Example1 – it brings 1:1 architecture replacement. The same sets of ISA cards are mounted on USBISA or USBISA-x3 cards, and serviced from one Host computer system. The service software for the individual ISA cards is transferred to the host system, which manages and controls them .

    more isa 2

    Example2 – it brings a possible architecture replacement. The same number of ISA cards are mounted on two USBISA-x3 cards, and serviced from one Host computer system .

    If the functions performed by ISA card type3 on Computer system2 allow, and there are no other conditions or limits, the card may be placed and serviced together with type1/type2 ISA cards, on a single USBISA-x3 card.

    The service software for the individual ISA cards, transferred to the host system, has to manage them according to their functions.

    pc104 set 1

    4. Architecture variety The examples shown above may be applied to servicing PCMCIA cards on USBPCMCIA products as well.

    There is only one host in the above examples. When the number of ISA cards which need to be serviced grows the number of Host computer systems may grow as well.

    The number of Host computer systems, the number of ISA cards per Host system, and the way to mount ISA cards, depends on many factors, including –

  • The amount of data going through each ISA card
  • If needed time critical servicing
  • Location and distance on the original computer systems

    We plan to introduce USB to PCI interface card, and the same architecture can be applied to these cards as well.