ENK32通用電氣模塊，GE使用指導
AM79C90執行DMA操作以執行其正常工作功能。MVME147將AM79C90 DMA限制為本地DRAM只有AM79C90無(wú)法訪(fǎng)問(wèn)VMEbus。如果DRAM大小為小于16MB，然后在A(yíng)M79C90 16MB內存中重復地圖如果大于16MB，則AM79C90訪(fǎng)問(wèn)由中的LANA24和LANA25位定義的DRAM部分PCC從基址寄存器（FFFE102B的第6位和第7位）。
ENK32通用電氣模塊每個(gè)MVME147分配一個(gè)以太網(wǎng)站地址。這個(gè)地址是$08003E2xxxxx，其中xxxxx是唯一編號分配給模塊（即，每個(gè)MVME147具有不同的值對于xxxxx）。每個(gè)以太網(wǎng)站地址都顯示在連接到MVME147的背板連接器P2。此外，xxxxx部分以太網(wǎng)站地址的第個(gè)地址存儲在BBRAM中，位置$FFFE0778作為$2xxxxx。如果摩托羅拉網(wǎng)絡(luò )軟件在MVME147上運行，那么使用BBRAM中的2xxxxx值來(lái)完成以太網(wǎng)車(chē)站地址（$08003E2xxxxx）。用戶(hù)必須確保在BBRAM中保持2xxxxx的值。如果2xxxxx的值為
在BBRAM中丟失時(shí)，用戶(hù)應使用P2連接器恢復。注意，MVME147bug包括
用于檢查和更新BBRAM xxxxx的“LSAD”命令價(jià)值如果非摩托羅拉網(wǎng)絡(luò )軟件在MVME147上運行，它必須設置AM79C90，以便以太網(wǎng)站地址為標簽上顯示的，以確保模塊具有全局唯一的以太網(wǎng)站地址。
SCSI接口MVME147具有SCSI大容量存儲總線(xiàn)接口。SCSI總線(xiàn)用于將大容量存儲子系統連接到
MVME147。這些子系統可能包括硬盤(pán)和軟盤(pán)驅動(dòng)器、流式磁帶驅動(dòng)器和其他大容量存儲設備。SCSI接口使用WD33C93控制器實(shí)現。與WD33C93之間的DMA通過(guò)PCC實(shí)現。
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.
