PCI bus with reduced number of signals
First Claim
1. An apparatus comprising:
- a CPU;
a PCI bus coupled to said CPU;
a first PCI/MPCI bridge coupled to said PCI bus and configured to be accessed by said CPU via said PCI bus;
a MPCI bus coupled to said first PCI/MPCI bridge; and
an external device coupled to said MPCI bus and configured to be accessed by said first PCI/MPCI bridge via said MPCI bus,wherein said first PCI/MPCI bridge is further configured to convert an incoming PCI transaction as received via said PCI bus into an incoming MPCI transaction by time-division multiplexing two or more incoming PCI signals within said incoming PCI transaction into a single incoming MPCI signal, and converting an outgoing MPCI transaction as received via said MPCI bus into an outgoing PCI transaction by de-multiplexing at least one outgoing MPCI signal within said outgoing MPCI transaction into two or more outgoing PCI signals, and wherein said incoming PCI transaction includes a plurality of incoming PCI signals and said outgoing PCI transaction includes a plurality of outgoing PCI signals which are selected from a group consisting of control signals, address signals and data signals.
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Accused Products
Abstract
A Mini-PCI (MPCI) interface, and associated circuits and methods are provided for connecting a Peripheral Component Interconnect (PCI) device to one or more external devices. The MPCI interface, circuits and methods provide for a substantial if not full implementation of a PCI Local Bus without requiring the standard number of pins, traces, or signals. The MPCI interface includes a PCI/MPCI bridge connected between a PCI bus and to up to eight external devices in the form of MPCI devices and linear memory devices. The PCI/MPCI bridge is capable of receiving an incoming PCI transaction and multiplexing some of its signals together to create a corresponding incoming MPCI transaction. This incoming MPCI transaction may then be passed over an MPCI bus, having fewer lines and optimally operating at a higher frequency, the external devices. The process is reversed for outgoing transactions, i.e., the MPCI transactions are de-multiplexed to create PCI transactions. Additionally, the MPCI interface may also be configured to provide for direct access to linearly addressed memory devices without adding a PCI interface to the external interface. The invention may be implemented through integrated circuitry and/or computer implemented instructions, and may be included within a personal computer.
83 Citations
22 Claims
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1. An apparatus comprising:
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a CPU; a PCI bus coupled to said CPU; a first PCI/MPCI bridge coupled to said PCI bus and configured to be accessed by said CPU via said PCI bus; a MPCI bus coupled to said first PCI/MPCI bridge; and an external device coupled to said MPCI bus and configured to be accessed by said first PCI/MPCI bridge via said MPCI bus, wherein said first PCI/MPCI bridge is further configured to convert an incoming PCI transaction as received via said PCI bus into an incoming MPCI transaction by time-division multiplexing two or more incoming PCI signals within said incoming PCI transaction into a single incoming MPCI signal, and converting an outgoing MPCI transaction as received via said MPCI bus into an outgoing PCI transaction by de-multiplexing at least one outgoing MPCI signal within said outgoing MPCI transaction into two or more outgoing PCI signals, and wherein said incoming PCI transaction includes a plurality of incoming PCI signals and said outgoing PCI transaction includes a plurality of outgoing PCI signals which are selected from a group consisting of control signals, address signals and data signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A circuit for coupling one or more external devices to a PCI bus, said circuit comprising:
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a PCI-to-PCI bridge capable of being coupled to said PCI bus and configured to send and receive PCI transactions over said PCI bus, wherein each of said PCI transactions includes a plurality of PCI signals which are selected from a group consisting of control signals, address signals and data signals; and a multiplexing/de-multiplexing stage coupled to said PCI-to-PCI bridge and configured to convert at least one of said PCI transactions into at least one MPCI transaction comprising a plurality of MPCI signals, by time-division multiplexing two or more of said plurality of PCI signals into at least one of said plurality of MPCI signals, and to convert said MPCI transactions into at least one PCI transaction, by time-division de-multiplexing one or more of said plurality of MPCI signals to create at least two of said plurality of PCI signals, and wherein said multiplexing/de-multiplexing stage is capable of being coupled to said at least one of said one or more external devices so as to receive MPCI transactions therefrom and send MPCI transactions thereto. - View Dependent Claims (13, 14, 15)
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16. A method for coupling a PCI bus to one or more external devices, said method comprising:
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receiving an incoming PCI transaction from said PCI bus, wherein said incoming PCI transaction includes a plurality of incoming PCI signals selected from a group consisting of control signals, address signals and data signals; time-division multiplexing at least two of said plurality of incoming PCI signals to generate at least one incoming MPCI signal; time-division de-multiplexing said incoming MPCI signal to re-generate said at least two of said plurality of incoming PCI signals; and providing said re-generated plurality of incoming PCI signals to said one or more external devices. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A means for coupling one or more external devices to a PCI bus, said means comprising:
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a bridge means for sending and receiving PCI transactions over said PCI bus; and a conversion means for converting at least one of said PCI transactions into at least one second bus transaction comprising a plurality of second bus signals, by time-division multiplexing two or more of a plurality of PCI signals within said PCI transaction into at least one of said plurality of second bus signals, and converting said second bus transactions into at least one PCI transaction, by time-division de-multiplexing one or more of said plurality of second bus signals to create at least two of said plurality of PCI signals.
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Specification