參數(shù)資料
型號(hào): AM79C972
廠商: Advanced Micro Devices, Inc.
英文描述: PCnet⑩-FAST+ Enhanced 10/100 Mbps PCI Ethernet Controller with OnNow Support
中文描述: PCnet⑩與OnNow增強(qiáng)10/100 Mbps的快速以太網(wǎng)控制器支持的PCI
文件頁數(shù): 76/130頁
文件大?。?/td> 1580K
代理商: AM79C972
76
Am79C972
Figure 41.
EPROM Only Configuration for the Expansion Bus (>64K EPROM)
Since setting MEMEN also enables memory mapped
access to the I/O resources, attention must be given to
the PCI Memory Mapped I/O Base Address register,
before enabling access to the Expansion ROM. The
host must set the PCI Memory Mapped I/O Base Ad-
dress register to a value that prevents the Am79C972
controller from claiming any memory cycles not in-
tended for it.
During the boot procedure, the system will try to find an
Expansion ROM. A PCI system assumes that an Ex-
pansion ROM is present when it reads the ROM signa-
ture 55h (byte 0) and AAh (byte 1).
Direct Flash Access
Am79C972 controller supports Flash as an Expansion
ROM device, as well as providing a read/write data
path to the Flash. The Am79C972 controller will sup-
port up to 1 Mbyte of Flash on the Expansion Bus. The
Flash is accessed by a read or write to the Expansion
Bus Data port (BCR30). The user must load the upper
address EPADDRU (BCR 29, bits 3-0) and then set the
FLASH (BCR29, bit 15) bit to a 1. The Flash read/write
utilizes the PCI clock instead of the EBCLK during all
accesses. EPADDRU is not needed if the Flash size is
64K or less, but still must be programmed. The user will
then load the lower 16 bits of address, EPADDRL (BCR
28, bits 15-0).
Flash/EPROM Read
A read to the Expansion Bus Data Port (BCR30) will
start a read cycle on the Expansion Bus Interface. The
Am79C972 controller will drive EBUA_EBA[7:0] with
the most significant address byte at the same time the
Am79C972 controller will drive AS_EBOE high to
strobe the address in the external
374 (D flip-flop). On
the next clock, the Am79C972 controller will drive
EBDA[15:8] and EBUA_EBA[7:0] with the middle and
least significant address bytes.
EBUA_EBA[7:0]
EBDA[15:8]
EBD[7:0]
EBWE
EROMCS
A[15:8]
A[7:0]
DQ[7:0]
CS
OE
Am79C972
EPROM
AS_EBOE
374
D-FF
A[23:16]
21485C-44
相關(guān)PDF資料
PDF描述
AM79C972BVIW PCnet⑩-FAST+ Enhanced 10/100 Mbps PCI Ethernet Controller with OnNow Support
AM79C974 PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
AM79C974KCW PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
AM79C975 PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
AM79C973 PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C972BKC\\W 制造商:Advanced Micro Devices 功能描述:
AM79C972BKC\W 制造商:Advanced Micro Devices 功能描述:
AM79C972BKCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet⑩-FAST+ Enhanced 10/100 Mbps PCI Ethernet Controller with OnNow Support
AM79C972BKD/W 制造商:Advanced Micro Devices 功能描述:
AM79C972BKD\\W 制造商:Advanced Micro Devices 功能描述: