ENK32通用电气模块，GE使用指导

AM79C90执行DMA操作以执行其正常工作功能。MVME147将AM79C90 DMA限制为本地DRAM只有AM79C90无法访问VMEbus。如果DRAM大小为小于16MB，然后在AM79C90 16MB内存中重复地图如果大于16MB，则AM79C90访问由中的LANA24和LANA25位定义的DRAM部分PCC从基址寄存器（FFFE102B的第6位和第7位）。

ENK32通用电气模块每个MVME147分配一个以太网站地址。这个地址是$08003E2xxxxx，其中xxxxx是唯一编号分配给模块（即，每个MVME147具有不同的值对于xxxxx）。每个以太网站地址都显示在连接到MVME147的背板连接器P2。此外，xxxxx部分以太网站地址的第个地址存储在BBRAM中，位置$FFFE0778作为$2xxxxx。如果摩托罗拉网络软件在MVME147上运行，那么使用BBRAM中的2xxxxx值来完成以太网车站地址（$08003E2xxxxx）。用户必须确保在BBRAM中保持2xxxxx的值。如果2xxxxx的值为

在BBRAM中丢失时，用户应使用P2连接器恢复。注意，MVME147bug包括

用于检查和更新BBRAM xxxxx的“LSAD”命令价值如果非摩托罗拉网络软件在MVME147上运行，它必须设置AM79C90，以便以太网站地址为标签上显示的，以确保模块具有全局唯一的以太网站地址。

SCSI接口MVME147具有SCSI大容量存储总线接口。SCSI总线用于将大容量存储子系统连接到

MVME147。这些子系统可能包括硬盘和软盘驱动器、流式磁带驱动器和其他大容量存储设备。SCSI接口使用WD33C93控制器实现。与WD33C93之间的DMA通过PCC实现。

The AM79C90 performs DMA operations to perform its normal

functions. The MVME147 restricts AM79C90 DMA to local DRAM

only. The AM79C90 cannot access the VMEbus. If the DRAM size is

less than 16MB then it repeats itself in the AM79C90 16MB memory

map. If it is more than 16MB, then the AM79C90 accesses the

section of DRAM defined by the LANA24 and LANA25 bits in the

PCC Slave Base Address Register (bits 6 and 7 of $FFFE102B).

Every MVME147 is assigned an Ethernet station address. The

address is $08003E2xxxxx where xxxxx is the unique number

assigned to the module (i.e., every MVME147 has a different value

for xxxxx).

Each Ethernet station address is displayed on a label attached to the

MVME147’s backplane connector P2. In addition, the xxxxx portion

of the Ethernet station address is stored in BBRAM, location

$FFFE0778 as $2xxxxx.

If Motorola networking software is running on an MVME147, it

uses the 2xxxxx value from BBRAM to complete the Ethernet

station address ($08003E2xxxxx). The user must assure that the

value of 2xxxxx is maintained in BBRAM. If the value of 2xxxxx is

lost in BBRAM, the user should use the number on the label on the

P2 connector to restore it. Note that MVME147bug includes the

“LSAD” command for examining and updating the BBRAM xxxxx

value. If non-Motorola networking software is running on an MVME147,

it must set up the AM79C90 so that the Ethernet station address is

that shown on the label to ensure that the module has a globally

unique Ethernet station address.

SCSI Interface

The MVME147 has a SCSI mass storage bus interface. The SCSI bus

is provided to allow mass storage subsystems to be connected to the

MVME147. These subsystems may include hard and floppy disk

drives, streaming tape drives, and other mass storage devices.

The SCSI interface is implemented using the WD33C93 controller.

DMA to/from the WD33C93 is implemented through the PCC.