i/oZONE Products for the week of November 18, 2002
IDT says . . .
PCI Punch-Up - IDT's Integrated Processor Boosts System
Bandwidth Through On-Chip Ethernet, PCI Optimization, And DDR Memory
IDT has expanded its Interprise family with the introduction of its RC32438 integrated communications processor. The newest member of IDT's Interprise-PCI offering delivers enhanced system bandwidth to communications applications within the Enterprise and access market segments, including desktop/workgroup switches, gateways, wireless access points (WAPs) and virtual private network (VPN) equipment. The RC32438 Interprise-PCI integrated communications processor also serves as a platform for IDT to develop future products that target emerging market segments such as embedded security and converged gateways.
IDT's focus on boosting bandwidth is driven by the growing requirements for higher sustained data rates and increased processing of data passing through the system. For example, Layer-2 desktop switching platforms are starting to support gigabit Ethernet local area network (LAN) connections in addition to the 10/100 Mbps connections previously deployed, and are also starting to incorporate certain Layer-3 data processing functions. In addition to the increasing performance demands in the Ethernet switch arena, wireless access points in the Enterprise are evolving to dual-mode radios and higher throughput 802.11 standards, and Enterprise gateways are integrating security functionalities on-chip. The RC32438 device addresses these performance and market demands and offers a natural upgrade path for customers using other IDT Interprise-PCI processors, allowing them to create higher-performance systems while leveraging their existing application software.
The RC32438 integrated communications processor incorporates a 32-bit MIPS CPU core with a double data rate (DDR) memory controller, a 32-bit version 2.2 peripheral component interconnect (PCI) controller and two on-chip Ethernet interfaces. Designers have a choice of popular embedded operating systems, including VxWorks and Linux, and a broad selection of development tools that reduce project design cycles and improve time-to-market.
"Devices from IDT's Interprise-PCI family have established a leadership position as the control processors of choice for managed Layer-2 switching systems," said Phil Bourekas, vice president of IDT's Internetworking Products Division. "Our RC32438 integrated communications processor offers an unprecedented combination of on-chip features, optimized system performance, third-party development tools, and cost-sensitivity. In addition, the device's backward compatibility with existing products helps our customers preserve their investment in software and development tools for their next generation of systems, and enables a broader reach into emerging Enterprise applications."
On-Chip Peripherals Drive System Bandwidth
The RC32438 integrated communications processor includes several key design
features that contribute to boosting system bandwidth. The integration of
two Ethernet interfaces reduces the level of bus traffic on other shared
external buses and frees up bandwidth for use by other peripherals, improving
system bandwidth and reducing overall system cost. The PCI bus interface
is an industry-standard interface with a broad range of supporting low-cost,
networking, storage and graphics peripherals. IDT's PCI bus controller on
the RC32438 device is optimized for bursting data and is designed to provide
continuous bursting for sustained throughput. The RC32438 device also incorporates
a DDR memory controller that provides system designers with higher memory
bandwidth systems than SDRAM-based solutions. Uniquely, the device also
includes logic that allows the monitoring of transactions on the IPBus,
the on-chip bus that connects the majority of the I/O peripherals, providing
customers an opportunity to tune the device to optimize performance for
an individual system configuration.
"From the outset, our aim was to design a well-balanced embedded processor, capable of delivering the right combination of memory bandwidth, system performance and CPU processing, to address performance requirements of key systems and enable the provision of value-added services," said Ian Ferguson, strategic marketing manager for IDT's Internetworking Products Division. "Our standpoint is that high-performance CPU cores are pointless if they cannot be fed, and high theoretical system bandwidth is meaningless if the CPU is not able to process the data quickly enough, so we ensured that our RC32438 integrated communications processor addresses both of these requirements."
Multiple General-Purpose Peripherals
The RC32438 processor also includes a local memory I/O controller, three
general-purpose counter/timers, a ten channel DMA controller, an I2C bus
controller, two serial ports, an interrupt controller, a general-purpose
I/O controller, and a serial peripheral interface (SPI).
Broad Choice of Development Tools
The use of the 4Kc CPU core from MIPS Technologies in IDT's RC32438 integrated
communications processor allows customers to select from a broad range of
generic development tools, including compilers, in-circuit emulators and
real-time operating systems. IDT is already providing optimized VxWorks
and embedded Linux solutions for the 79EB438 evaluation platform to enable
customers to benchmark or prototype application software ahead of the availability
of their own hardware. The device is also supported by a diverse range of
in-circuit emulator equipment compatible with the enhanced JTAG (EJTAG)
interface to help speed hardware/software integration tasks.
analogZONE Says . . .
I congratulate IDT on its efforts to bring intelligence to the control plane in PCI-based equipment. Like it or not, the PCI bus will be around for at least another few years as the workhorse bus in medium-level networking and access equipment. Now IDT has given us a controller that helps get around at least some of the more painful constraints normally faced by PCI-based designs.
In developing this line of smart I/O controllers, they have taken note of the fact that communications and networking systems are cramming larger numbers of higher speed I/O channels into their boxes and, more important, integrating multiple functions that would have been separate products a year or two ago into single boxes. We're already seeing VPN boxes that handle tunneling, encryption, and connection management, and can probably expect it to be absorbed into routers or access/gateway equipment. DSL, cable and other broadband gateways are already integrating WLAN, router, and firewall functions, and will probably sport even more functions while bandwidth continues to grow. This trend will fuel a big demand for QoS to support multimedia applications that demand intelligence for access equipment.
To meet these demands, IDT's RC32438 PCI controller is designed to help aggregate PCI-based control connections within network equipment and pass them through in an efficient manner. This is essential because the poor PCI bus was designed for the relatively simple PC environment and these multistream, control applications place a great strain on both its architecture and its limited bandwidth. The RC32438 was designed to act as a host system controller for Broadcom and Intel switch chip sets and is working on applications with Marvell.
By concentrating and grooming the control signals, the controller makes it easy for multiple switch fabric chips to share a PCI bus efficiently. This makes it much easier to handle the routing table updates, messaging, exception processing, MIB exchange, statistics collection, and configuration management tasks at speeds that can match the throughputs of modern CPU cores.
To accomplish this, the controller "ups" its memory access speed using an on-chip DDR controller with a bus that can handle the full rate. This allows it to connect memory and peripherals to the main system efficiently. A separate bus that decouples the memory controller/CPU core subsystem from on-chip peripherals residing on the IPBus. By ensuring memory/CPU operation is not stalled by contention on the IPBus, transactions can reliably run at the CPU's full pipeline rate. This nice architecture also allows designers to exploit ways to speed up PCI bus in proprietary ways for closed systems where compatibility does not matter. For the real speed-freak applications, it eliminates dead cycles and maximum transfer limits imposed by the PCI standard.
Besides giving the PCI bus the moral equivalent of a powerful laxative, the RC32438 provides developers and service people with some very sophisticated debug capabilities. The chip's on-board MIPS processor, memory and support circuits provide a "soft logic analyzer" to record bus transactions and play them back in case of a crash. You can even use it to set break points and trigger conditions, and extract time stamps to track down even intermittently occurring conditions.
This chip will most certainly find many applications controlling large clusters of Fast/Gigabit switch ports, and serving as a controller in enterprise-class wireless access point equipment. It should also be welcomed in bridging applications, such as efficiently connecting a security processor to the rest of a high-performance VPN box. Pricing starts at $25 in 10-k piece lots.
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