Emerson Motorola MVME197LE, User Manual

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Functional Description
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All four serial ports use EIA-232-D drivers and receivers located on the main
board, and all the signal lines are routed to the I/O connector. The
configuration headers are located on the MVME712X transition board. An
external I/O transition board such as the MVME712X should be used to
convert the I/O connector pinout to industry-standard connectors.
The interface provided by the PCCchip2 allows the 16-bit CD2401 to appear at
contiguous addresses; however, accesses to the CD2401 must be 8 or 16 bits.
32-bit accesses are not permitted. Refer to the CD2401 data sheet and to the
PCCchip2 chapter in the MVME197LE, MVME197DP, and MVME197SP Single
Board Computers Programmer’s Reference Guide for detailed programming
information.
The CD2401 supports DMA operations to local memory. Because the CD2401
does not support a retry operation necessary to break VMEbus lock conditions,
the CD2401 DMA controllers should not be programmed to access the
VMEbus. The hardware does not restrict the CD2401 to onboard DRAM.
Printer Interface
The MVME197LE has a Centronics-compatible printer interface. The printer
interface is provided by the PCCchip2. Refer to the PCCchip2 chapter in the
MVME197LE, MVME197DP, and MVME197SP Single Board Computers
Programmer’s Reference Guide for detailed programming information and for
drawings of the printer port interface connections.
Ethernet Interface
The 82596CA is used to implement the Ethernet transceiver interface. The
82596CA accesses local RAM using DMA operations to perform its normal
functions. Because the 82596CA has small internal buffers and the VMEbus
has an undefined latency period, buffer overrun may occur if the DMA is
programmed to access the VMEbus. Therefore, the 82596CA should not be
programmed to access the VMEbus.
Every MVME197LE module is assigned an Ethernet Station Address. This
address is $08003E2XXXXX, where XXXXX is the unique 5-nibble number
assigned to the board (i.e., every MVME197LE has a different value for
XXXXX).
The Ethernet Station Address is displayed on a label attached to the VMEbus
P2 connector. In addition, the eight bytes including the Ethernet address are
stored in the configuration area of the BBRAM, with the two lower bytes of
those set to 0. That is, 08003E2XXXXX0000 is stored in the BBRAM. At an
address of $FFFC1F2C, the upper four bytes (08003E2X) can be read. At an
address of $FFFC1F30, the lower four bytes (XXXX0000) can be read. Refer to