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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