SERIAL PORT ACCESS SYSTEM AND METHOD IN A COMPUTING SYSTEM

1 . A multiple-card computing system, comprising:

a first card comprising a plurality of first devices having serial ports, the plurality of first devices including a first inter-card serial connection;

a second card comprising a plurality of second devices having serial ports, the plurality of second devices including a first inter-card serial connection;

an inter-card serial bus connecting the first inter-card serial connection of the first card with the second inter-card serial connection of the second card;

a serial port access system for providing a dynamically selectable serial connection between any of the first devices and any of the second devices, comprising:

a first switch on the first card, the first switch configured to provide switchable serial connections between any of the first devices;

a second switch on the second card, the second switch configured to provide switchable serial connections between any of the second devices; and

an inter-card signaling system configured to communicate switching instructions between the first and second cards;

wherein the serial port access system is programmed to provide a serial connection between a particular first device and a particular second device by:

the first switch on the first card dynamically connecting the particular first device with the first inter-card serial connection; and

the second switch on the first card dynamically connecting the particular second device with the second inter-card serial connection, in response to switching instructions received via the inter-card signaling system;

such that a serial connection is provided between the particular first device and the particular second device via the first inter-card serial connection, the inter-card serial bus, and the second inter-card serial connection.

2 . The system of claim 1 , wherein the inter-card serial bus utilizes multipoint low-voltage differential signaling (MLVDS).

3 . The system of claim 1 , wherein the inter-card signaling system utilizes I2C signaling system.

4 . The system of claim 1 , wherein the inter-card signaling system is physically distinct from the inter-card serial bus.

5 . The system of claim 1 , wherein the first switch is embodied in a configurable logic device.

6 . The system of claim 5 , wherein the first switch is embodied in a complex programmable logic device (CPLD).

7 . A computing system, comprising:

a card configured for connection with at least one other card, the card comprising:

a plurality of devices having serial ports, the plurality of devices including an inter-card serial connection;

an inter-card serial bus connection configured for connection to an inter-card serial bus;

a serial port access system for providing a dynamically selectable serial connection between any of the devices on the card and between any device on the card and any device on the at least one other card having a serial port, the serial port access system comprising:

a switch configured to provide switchable serial connections between any of the devices on the card;

an inter-card signaling system configured to communicate switching instructions from the card for receipt by the at least one other card;

wherein the serial port access system is programmed to provide a serial connection between a particular device on the card and a target device on another card by:

controlling the switch to connect the particular device with the inter-card serial bus connection; and

the inter-card signaling system communicating switching instructions for receipt by the other card to enable a connection between the target device and the inter-card serial bus, such that a serial connection is provided between the particular device and the target device via the inter-card serial bus.

8 . The system of claim 7 , wherein the inter-card serial bus utilizes multipoint low-voltage differential signaling (MLVDS).

9 . The system of claim 7 , wherein the inter-card signaling system utilizes I2C signaling system.

10 . The system of claim 7 , wherein the inter-card signaling system is physically distinct from the inter-card serial bus.

11 . The system of claim 7 , wherein the switch is embodied in a configurable logic device.

12 . The system of claim 11 , wherein the switch is embodied in a complex programmable logic device (CPLD).

13 . A method for providing a serial connection between a particular first device on a first card and a particular second device on a second card in a multiple-card computing system, the method comprising:

controlling a first switch on the first card to provide a serial connection between the particular first device on the first card and a first inter-card serial connection on the first card, the first inter-card serial connection being connected to an inter-card serial bus;

an inter-card signaling system communicating switching instructions to the second card; and

in response to receiving the switching instructions, controlling the second switch on the second card to provide a serial connection between the particular second device on the second card and a second inter-card serial connection on the second card, the second inter-card serial connection being connected to the inter-card serial bus;

such that a serial connection is provided between the particular first device and the particular second device via the first inter-card serial connection, the inter-card serial bus, and the second inter-card serial connection.

14 . The method of claim 13 , wherein the inter-card serial bus utilizes multipoint low-voltage differential signaling (MLVDS).

15 . The method of claim 13 , wherein the inter-card signaling system utilizes I2C signaling system.

16 . The system of claim 13 , wherein the inter-card signaling system is separate from communications via the inter-card serial bus.