BCM1122A4KEB

Overview

The Broadcom BCM1122A4KEB is a high-performance system-on-a-chip processor featuring a 400-MHz MIPS64 SB-1 CPU. It integrates a shared 128-KB L2 cache with ECC protection, a DDR memory controller supporting SDRAM and FCRAM, and an on-chip ZBbus operating at 51 Gbps bandwidth. The device includes one Gigabit Ethernet MAC (configurable as an 8-bit FIFO), one Fast Ethernet MAC, a 32-bit PCI interface, two serial interfaces, and generic I/O for direct peripheral connection. Designed for low power consumption at 4W, it supports big- or little-endian modes.

Feature Summary

• MIPS64 SB-1 CPU core with quad-issue pipeline and zero load-to-use penalty
• Integrated 128-KB four-way associative L2 cache with ECC protection
• Dual Ethernet MACs: one 10/100/1000 Mbps and one 10/100 Mbps
• PCI 2.2 interface supporting 33/66 MHz host bridge or target modes

Applications

• Networking routers and switches
• Broadband access systems including DSLAM, CMTS, and BRAS
• Wireless base stations
• Storage controllers such as RAID and NAS
• Imaging devices like printers and copiers

Procurement Notes

Verify the specific suffix 'A4KEB' against official Broadcom documentation to confirm package type, temperature range, and lead time specifications. Ensure compatibility with existing BSPs and firmware libraries designed for the BCM1122 family before procurement.

Selection Notes

Select this component for applications requiring software compatibility with the BCM1125H and BCM1250 processors. It is suitable for designs needing integrated Ethernet MACs and PCI connectivity without external glue logic. Consider the 4W power dissipation and 0.13-micron process technology for thermal management in compact enclosures.

Part Context

The BCM1122 belongs to Broadcom's networking processor family, sharing architectural similarities with the BCM1125H and BCM1250. It utilizes the MIPS64 ISA and is manufactured using TSMC's 0.13-micron process. The chip is housed in a pin-compatible 31-mm BGA package, facilitating design reuse across different product tiers within the same ecosystem.

Replacement Considerations

The BCM1122 is software-compatible with the BCM1125H and BCM1250. These parts share development tools and operating systems. Verify pinout and electrical characteristics when substituting between these models to ensure hardware compatibility.