Four MCM4464 modules comprise a full 1 MB of secondary cache for the R4000 processor. Each module contains nine MCM6709J fast static RAMs for a cache data size of 64K x 36. The tag portion, dependent on word line size, contains either two MCM6709J or one MCM6706J fast static RAMs. All input signals, except A0 and WE are buffered using 74FBT2827 drivers with series 25 Ω resistors. The MCM6709J and MCM6706J are fabricated using high–performance silicon–gate BiCMOS technology. Static design eliminates the need for internal clocks or timing strobes.
All 1MB R4000 supported secondary cache options are available.

• Single 5 V ± 10% Power Supply
• All Inputs and Outputs are TTL Compatible
• Three State Outputs
• Fast Module Access Time: 12/15/17 ns
• Zero Wait–State Operation
• Unified or Split Seconday Cache Modules are Available (See Ordering Information for Details)
• Word Line Sizes of 4, 8, 16, and 32 are Available (See Ordering Information for Details)
• The Pin Compatible MCM44256 Series is also Available to Support a Full 4MB R4000 Secondary Cache.
• Decoupling Capacitors are Used for Each Fast Static RAM and Buffer, Along with Bulk Capacitance for Maximum Noise Immunity
• High Quality Multi–Layer FR4 PWB with Separate Power and Ground Planes