Renesas 89HPES24T6ZCBX

Overview

89HPES24T6ZCBX from IDT is a 24-lane, 6-port PCI Express Gen2 switch IC designed for high-throughput I/O expansion in servers and storage systems. It supports 5 Gbps per lane, up to six configurable ports (one upstream + five downstream), full PCIe Base Specification 2.0 compliance, and integrated SerDes with on-chip packet buffering.

For engineers reviewing the 89HPES24T6ZCBX datasheet, 89HPES24T6ZCBX pinout, 89HPES24T6ZCBX application, or 89HPES24T6ZCBX equivalent, key selection criteria include Gen2 lane count scalability, hot-plug support across all downstream ports, RAS features like ECRC and SECDED ECC, and flexible SMBus-based configuration via serial EEPROM.

Technical Context

The 89HPES24T6ZCBX implements a layered PCI Express architecture compliant with Base Spec 2.0, integrating SerDes, Physical, Data Link, and Transaction layers. It operates in either store-and-forward or cut-through mode and supports eight traffic classes and one virtual channel for QoS-aware switching.

Its flexible port configuration includes automatic link width negotiation (x1/x2/x4/x8), dynamic reconfiguration, crosslink capability, and ARI forwarding for virtualized environments. Power management includes ASPM L0s/L1 states, SerDes transmit voltage margining, and unused SerDes shutdown.

Key Specifications

Pinout & Package

89HPES24T6ZCBX is packaged in a 27 mm × 27 mm 676-ball Flip Chip BGA with 1 mm ball pitch (Option B). The package supports full pin functionality including dual SMBus interfaces, 11 GPIOs, JTAG test access, and dedicated reference clock and SerDes bias resistor pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCI Express switching applications.

Compared with 89HPES24T6ZABX, the 89HPES24T6ZCBX provides full debug visibility, flexible clock configuration, and expanded I/O for system-level control - critical for validation and field service in enterprise infrastructure.

Availability

89HPES24T6ZCBX is available at Aetrix Electronics and suitable for server I/O expansion, enterprise storage controllers, communications backplanes, and embedded computing platforms requiring stable component supply and long-term lifecycle support.

Supply support for 89HPES24T6ZCBX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

IDT (Integrated Device Technology, Inc.) is a fabless semiconductor company specializing in high-performance timing, memory interface, and interconnect solutions, now part of Renesas Electronics.

The 89HPES24T6ZCBX belongs to IDT's PRECISE™ family of PCIe switches, engineered specifically for high-bandwidth, low-latency I/O consolidation in data center and telecom infrastructure.

FAQ

What is the primary function of the 89HPES24T6ZCBX in a PCIe topology?

The 89HPES24T6ZCBX serves as a 24-lane, 6-port PCI Express Gen2 switch that routes traffic between an upstream host (e.g., CPU root complex) and up to five downstream endpoints. It performs store-and-forward or cut-through switching, supports peer-to-peer communication, and enables scalable I/O expansion without requiring changes to host software or firmware. Its role is foundational in PCIe tree topologies used in servers and storage arrays.

Does the 89HPES24T6ZCBX support hot-plug on all ports, and how is it implemented?

Yes, the 89HPES24T6ZCBX supports full PCI Express hot-plug on all six ports. It uses an external I/O expander connected via the master SMBus interface to manage hot-plug detect signals and generate SCI/SMI interrupts. When a card is inserted or removed, the I/O expander asserts IOEXPINTN, triggering the 89HPES24T6ZCBX to read status and initiate PCIe hot-plug enumeration - eliminating the need for dedicated hot-plug controller ICs.

How does the 89HPES24T6ZCBX handle PCIe reference clock configuration?

The 89HPES24T6ZCBX accepts a differential 100 MHz or 125 MHz reference clock via PEREFCLKP/PEREFCLKN. The frequency is selected by the REFCLKM pin: logic 0 = 100 MHz, logic 1 = 125 MHz. In the 27mm ZCBX package, REFCLKM is a user-configurable input; in the 19mm variant, it is omitted and defaults to 100 MHz. This clock feeds on-chip PLLs that generate all internal timing domains for SerDes and logic.

What debug and test capabilities does the 89HPES24T6ZCBX provide?

The 89HPES24T6ZCBX includes comprehensive debug features: full JTAG boundary scan (TCK/TDI/TDO/TMS/TRST_N), per-port PRBS generation and loopback testing, SMBus-accessible internal registers (including SerDes controls), and real-time link statistics. The RSTHALT pin allows halting post-reset to inspect configuration before initialization - a capability exclusive to the 27mm ZCBX package and essential for bring-up validation.

Can the 89HPES24T6ZCBX be configured without external EEPROM, and what interfaces support runtime reconfiguration?

Yes, the 89HPES24T6ZCBX supports both EEPROM-based boot configuration (via master SMBus) and runtime reconfiguration via slave SMBus or JTAG. All internal registers - including port arbitration tables, traffic class mappings, and SerDes settings - are accessible through the slave SMBus interface (address 0x77 default) or JTAG. This enables dynamic tuning of link widths, error reporting thresholds, and QoS policies without power cycling.