JEDEC announces the updated JESD235 High Bandwidth Memory (HBM) DRAM Standard used in graphics cards, high-performance computing, server, networking, and client applications. The standard was developed and updated with support from leading GPU and CPU developers to extend the system bandwidth growth curve beyond levels supported by traditional discrete packaged memory. The updated standard is named ‘JESD235B’.
JESD235B is available for download from the JEDEC website.
JEDEC standard JESD235B for HBM leverages Wide I/O and TSV technologies to support densities up to 24 GB per device at speeds up to 307 GB/s. This bandwidth is delivered across a 1024-bit wide device interface that is divided into 8 independent channels on each DRAM stack. The standard can support 2-high, 4-high, 8-high, and 12-high TSV stacks of DRAM at full bandwidth to allow systems flexibility on capacity requirements from 1 GB – 24 GB per stack.
This update extends the per-pin bandwidth to 2.4 Gbps, adds a new footprint option to accommodate the 16 Gb-layer and 12-high configurations for higher density components, and updates the MISR polynomial options for these new configurations. Additional clarifications are provided throughout the document to address test features and compatibility across generations of HBM components.