user manual

2-2
Board Level Hardware Description
2
Onboard Memory Mezzanine Module
The MVME187 onboard DRAM mezzanine boards are available in
different sizes and with programmable parity protection or Error
Checking and Correction (ECC) protection.
❏ The main board and a single mezzanine board together take
one slot.
❏ Motorola software supports mixed parity and ECC memory
boards on the same main board.
❏ Mezzanine board sizes are 4, 8, 16, or 32 MB (parity), or 4, 8,
16, 32, 64, or 128 MB (ECC);
Ð Two mezzanine boards may be stacked to provide 256MB
of onboard RAM (ECC) or 64 MB (parity). The stacked
configuration requires two VMEbus slots.
❏ The DRAM is four-way interleaved to efficiently support
cache burst cycles.
❏ The parity mezzanines are only supported on 25 MHz main
boards.
A functional description of the Onboard DRAM starts on page 2-15.
SCSI Mass Storage Interface
The MVME187 provides for mass storage subsystems through the
industry-standard SCSI bus. These subsystems may include
❏ Hard and floppy disk drives
❏ Streaming tape drives
❏ Other mass storage devices.
A functional description of the SCSI Interface starts on page 2-22.