Motorola MVME162 Manuale Utente

Pagina di 136
Board Level Hardware Description
1-18
MVME162 Embedded Controller Installation Guide
1
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 MVME162 that has the Ethernet interface is assigned an Ethernet Station 
Address. The address is $08003E2XXXXX where XXXXX is the unique 5-nibble 
number assigned to the board (i.e., every MVME162 has a different value for 
XXXXX).
Each board has an Ethernet Station Address displayed on a label attached to 
the VMEbus P2 connector. In addition, the six bytes including the Ethernet 
address are stored in the configuration area of the BBRAM. That is, 
08003E2XXXXX 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 two bytes (XXXX) can be read. The MVME162 debugger has the 
capability to retrieve or set the Ethernet address.
If the data in the BBRAM is lost, the user should use the number on the 
VMEbus P2 connector label to restore it.
The Ethernet transceiver interface is located on the MVME162 main board, and 
the industry DB15 standard connector is located on the MVME712X transition 
board.
Support functions for the 82596CA are provided by the MCchip ASIC. Refer to 
the 82596CA user’s guide for detailed programming information. 
Optional SCSI Interface
The MVME162 may provide for mass storage subsystems through the 
industry-standard SCSI bus. These subsystems may include hard and floppy 
disk drives, streaming tape drives, and other mass storage devices. The SCSI 
interface is implemented using the NCR 53C710 SCSI I/O controller.
Support functions for the 53C710 are provided by the MCchip ASIC. Refer to 
the 53C710 user’s guide for detailed programming information.
SCSI Termination
The system configurer must ensure that the SCSI bus is properly terminated at 
both ends. On the MVME162, sockets are provided for the terminators on the 
P2 adapter board or the LCP2 adapter board. If the SCSI bus ends at the 
adapter board, then termination resistors must be installed on the adapter 
board. +5V power to the SCSI bus TERM power line and termination resistors 
is provided through a fuse located on the adapter board.