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Vmebus interface, Asynchronous debug port, Vmebus interface -25 asynchronous debug port -25 – Motorola MVME2400 User Manual

Page 73: 3vmebus interface

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3-25

3

VMEbus Interface

The VMEbus interface is implemented with the CA91C142 Universe
ASIC. The Universe chip interfaces the 32/64-bit PCI local bus to the
VMEbus.

The Universe ASIC provides:

The PCI-bus-to-VMEbus interface

The VMEbus-to-PCI-bus interface

The DMA controller functions of the local VMEbus

The Universe chip includes Universe Control and Status Registers
(UCSRs) for interprocessor communications. It can provide the VMEbus
system controller functions as well. For detailed programming
information, refer to the Universe User’s Manual and to the discussions in
the MVME2400-Series VME Processor Module Programmer's Reference
Guide
.

Maximum performance is achieved with D64 Multiplexed Block
Transfers (MBLT). The on-chip DMA channel should be used to move
large blocks of data to/from the VMEbus. The Universe should be able to
reach 50MB/second in 64-bit MBLT mode.

The MVME2400 interfaces to the VMEbus via the P1 and P2 connectors,
which use the new 5-row 160-pin connectors as specified in the VME64
extension standard. It also draws +5V, +12V, and -12V power from the
VMEbus backplane through these two connectors. 3.3V and 2.5V supplies
are regulated onboard from the +5 power.

Asynchronous Debug Port

A Texas Instrument’s Universal Asynchronous Receiver/Transmitter
(UART) provides the asynchronous debug port. TTL-level signals for the
port are routed through appropriate EIA-232-D drivers and receivers to an
RJ45 connector on the front panel. The external signals are ESD protected.