Motorola MVME6100-0161 | VMEbus SBC with MPC7457 at 1.267 GHz & 2eSST

In the field, the biggest challenge with legacy VME systems is the VME bandwidth bottleneck. Standard VME64 tops out at 80 MB/s—fine for 1990s applications but completely inadequate for modern radar signal processing, high-definition video, medical imaging, or multi-axis motion control. The MVME6100-0161 solves this with the Tundra Tsi148 VME interface and 2eSST protocol

, delivering 320 MB/s actual bandwidth—4x the throughput of previous generations—while maintaining backward compatibility with existing VME backplanes and I/O cards.

You will typically find this board in next-generation military and aerospace systems (phased array radar, electronic warfare, mission computing), high-end industrial automation (machine vision, robotics, real-time control), medical imaging (CT/MRI reconstruction, ultrasound processing), and telecommunications infrastructure (protocol processing, network switching). It’s specifically designed for data-intensive applications

where the combination of 1.267 GHz processing, AltiVec vector acceleration, and 320 MB/s VME throughput enables real-time processing of massive data streams.

Its core value is breaking the VME bandwidth barrier while preserving infrastructure investment. The 2eSST protocol

uses both edges of the clock for data transfer, effectively doubling the data rate without requiring new backplane hardware—though it does require the Tsi148 interface chip and compatible VME64x backplanes. The dual Gigabit Ethernet

provides network-centric connectivity that matches the VME bus speed, eliminating the network bottleneck common in older designs. The DDR ECC memory

at 133 MHz provides the bandwidth to feed the processor and AltiVec unit without stalls. The dual PCI-X buses

—one for high-speed PMC modules, one dedicated to the VME bridge—prevent I/O contention and enable true parallel processing.

The 320 MB/s 2eSST protocol

requires a VME64x-compliant backplane with proper signal integrity and termination. A common field mistake is installing the MVME6100-0161 in a legacy VME64 backplane and expecting 2eSST speeds. The board will fall back to standard VME64 modes (80 MB/s or less), negating the performance advantage. Check your backplane specifications for “VME64x” and “2eSST support” before installation. If your backplane is only VME64, consider upgrading or accept the bandwidth limitation. The Tsi148 chip

auto-negotiates, but you won’t see the 4x speedup without proper infrastructure.

The dual Gigabit Ethernet ports

provide redundant or aggregated network connectivity, but they require Gigabit-capable switches and proper cabling (Cat5e or Cat6). A common pitfall is connecting to 100 Mbps switches or using Cat5 cable, then wondering why network throughput doesn’t improve. Also, the dual ports can be configured for redundancy (failover) or aggregation (bonding)—verify your software configuration matches your network architecture. If using VxWorks, ensure you have the correct END driver for the Marvell MV64360 Ethernet controller

.

The 128-bit AltiVec vector unit

provides massive performance gains, but only if your code is compiled with AltiVec support and proper data alignment. AltiVec loads/stores require 16-byte aligned data—unaligned access causes exceptions or performance degradation. Use compiler flags (-maltivec for GCC, -qaltivec for XL C) and verify your data structures are padded to 16-byte boundaries. A common field issue is porting code from MVME5500 (which also had AltiVec) but forgetting that the MVME6100 has different cache line sizes and memory timing—reprofile and reoptimize for the new architecture.

The dual PCI-X buses support 33/66/100 MHz operation

. A frequent pitfall is installing 33 MHz PMC cards in the 100 MHz slot, or forcing 100 MHz with 66 MHz-only cards. The MVME6100 has two distinct PCI-X segments: one dedicated to PMC at 100 MHz, one dedicated to the VME bridge at 133 MHz

. Verify your PMC card specifications and set jumpers accordingly. The PMCspan expansion

adds more PMC slots via a PCI6520 bridge—ensure this bridge is properly configured or you’ll see enumeration errors.

The 128 MB Flash is organized as dual 64 MB banks

. A dangerous pitfall is updating the primary boot image without verifying the backup image works. If the primary corrupts and the backup is blank or incompatible, the board bricks. Always maintain a known-good backup in the alternate bank. Use the S4 configuration switch

to select boot bank, and the write-protect jumpers to prevent accidental overwrites. The “Safe Start” header

forces default environment variables—use this if custom settings prevent boot.

The 512 MB base memory can expand to 1-2 GB via mezzanine cards

, but this increases power dissipation and blocks airflow. A common mistake is installing the mezzanine in a chassis with marginal cooling, causing thermal throttling or shutdown. The mezzanine sits directly above the processor—ensure no cables obstruct the heatsink. If running at +85°C ambient

, verify your chassis has 200+ LFM airflow. Consider removing the mezzanine if not absolutely required for your application.

In multi-board chassis, the System Controller (SCON) and VME Geographical Address must be uniquely configured. The S3 and S4 switches

set these parameters. Multiple SCON boards cause bus arbitration conflicts; duplicate geographical addresses cause CR/CSR space collisions. Check your chassis documentation—some backplanes have fixed SCON slots. The MVME6100 uses the Discovery II VME bridge

—its CR/CSR mapping differs from older Universe II chips. Verify your VME window mappings if migrating from MVME5500 or earlier.

While the MVME6100-0161 is pin-compatible with MVME5500

, the internal architecture differs significantly. The Tsi148 VME interface

has different programming models than the Universe II. VME DMA, interrupt handling, and CR/CSR access require driver updates. A common field issue is assuming MVME5500 VxWorks BSPs will work without modification—they won’t. Obtain the MVME6100-specific BSP from Emerson/Artesyn and recompile your application. The PCI-X bus timing also differs from the MVME5500’s PCI—verify PMC card compatibility.

The Motorola MVME6100-0161 represents the “VME Renaissance”

—a fundamental rethinking of VME architecture to break the 20-year bandwidth stagnation while preserving the ecosystem investment. It is the first VME board designed around the Tundra Tsi148 VME interface chip

, which implements the 2eSST protocol to achieve 320 MB/s sustained throughput.

The architecture centers on the MPC7457 PowerPC at 1.267 GHz

with integrated 128-bit AltiVec vector unit

. This provides SIMD (Single Instruction, Multiple Data) capabilities critical for DSP, image processing, and scientific computing. The 133 MHz DDR memory bus

with ECC support feeds the processor without bandwidth starvation.

The Tsi148 VME bridge

is the key innovation. Unlike previous VME interfaces that topped out at 80 MB/s, Tsi148 uses 2eSST (Dual Edge Source Synchronous Transfer)

—latching data on both rising and falling clock edges while using source-synchronous timing to eliminate skew. This requires VME64x backplanes with proper signal integrity, but delivers true 320 MB/s performance.

The Marvell MV64360 Discovery II system controller

integrates dual Gigabit Ethernet, PCI-X bridges, and memory control. This replaces multiple discrete chips, reducing board complexity and power consumption while improving reliability. The dual PCI-X buses

—one for PMC at 100 MHz, one for VME bridge at 133 MHz—prevent the I/O contention common in single-bus designs.

The MOTLoad firmware

provides board initialization, POST, and OS boot. It supports network boot (BOOTP/TFTP), Flash boot with redundant banks, and extensive diagnostics. The firmware is field-upgradable via Ethernet or serial, allowing feature enhancements without hardware replacement.

From a system architecture perspective, the MVME6100-0161 functions as a computational and I/O hub in next-generation VME systems. It can operate as VME bus master, slave, or system controller, with the Tsi148 chip providing advanced DMA, mailbox interrupts, and CR/CSR support. The deterministic VME64x timing, combined with PCI-X and AltiVec processing, makes this suitable for real-time signal processing, image analysis, and high-throughput data acquisition where latency and bandwidth are critical.

The board’s rugged design—extended temperature operation (-40°C to +85°C)

, shock/vibration tolerance, and ECC memory—reflects its target markets: military/aerospace (where VME remains the standard for mission-critical systems), high-performance industrial automation, medical imaging, and telecommunications infrastructure requiring 99.999% availability. The MVME6100 series specifically addresses the “VME bandwidth wall” that limited previous generations, enabling new applications that were previously impossible on the VME platform.