Introduction
Lucent Technologies Microelectronics Group has developed a solution for designers who need the many advantages of an FPGA-based design implementation, coupled with the high bandwidth of an industry-standard PCI interface. The ORCA OR3LP26B (a member of the Series 3+ FPSC family) provides a full-featured 33/50/66 MHz, 32-/64-bit PCI interface, fully designed and tested, in hardware, plus FPGA logic for user-programmable functions.

PCI Bus Core Highlights
■ Implemented in an ORCA Series 3 OR3L125B base array, displacing the bottom ten rows of 28 columns.
■ Core is a well-tested ASIC model.
■ Fully compliant to Revision 2.2 of PCI Local Bus specification.
■ Operates at PCI bus speeds up to 66 MHz on a 32-/64-bit wide bus.
■ Comprises two independent controllers for Master and Target.
■ Meets/exceeds all requirements for PICMG* Hot Swap friendly silicon, full Hot Swap model, per the CompactPCI* Hot Swap specification, PICMG 2.1 R1.0.
■ PCI SIG Hot Plug (R1.0) compliant.
■ Four internal FIFOs individually buffer both directions of both the Master and Target interfaces:
    — Both Master FIFOs are 64 bits wide by 32 bits deep.
    — Both Target FIFOs are 64 bits wide by 16 bits deep.
■ Capable of no-wait-state, full-burst PCI transfers in either direction, on either the Master or Target interface. The dual 64-bit data paths extend into the FPGA logic, permitting full-bandwidth, simultaneous bidirectional data transfers of up to 528 Mbytes/s to be sustained indefinitely.
■ Can be configured to provide either two 64-bit buses (one in each direction) to be multiplexed between Master and Target, or four independent 32-bit buses.
■ Provides many hardware options in the PCI core that are set during FPGA logic configuration.
■ Operates within the requirements of the PCI 5 V and 3.3 V signaling environments and 3.3 V commercial environmental conditions, allowing the same device to be used in 5 V or 3.3 V PCI systems.
■ FPGA is reconfigurable via the PCI interfaces configuration space (as well as conventionally), allowing the FPGA to be field-updated to meet latebreaking requirements of emerging protocols
■ Master:
    — Generates all defined command codes except interrupt acknowledge and special cycle.
    — Capable of accessing its own local Target.
    — Capable of acting as the systems configuration agent by booting up with the Master logic enabled.
    — Supports multiple options for Master bus requests, to increase PCI bus bandwidth.
    — Supports single-cycle I/O space accesses.
    — Provides option to delay PCI access until FIFO is full on Master writes to increase PCI bandwidth.
    — Supports programmable latency timer control.
■ Target:
    — Responds legally to all command codes: interrupt acknowledge, special cycle, and reserved commands ignored; memory read multiple and line handled as memory read; memory write and invalidate handled as memory write.
    — Implements Target abort, disconnect, retry, and wait cycles.
    — Handles delayed transactions.
    — Handles fast back-to-back transactions.
    — Method of handling retries is programmable at FPGA configuration to allow tailoring to different Target data access latencies.
    — Decodes at medium speed.
    — Provides option to delay PCI access until FIFO is full on Target reads to increase PCI bandwidth.
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