參數(shù)資料
型號: AM79C974KCW
廠商: ADVANCED MICRO DEVICES INC
元件分類: 微控制器/微處理器
英文描述: PCnetTM-SCSI Combination Ethernet and SCSI Controller for PCI Systems
中文描述: 2 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP132
封裝: PLASTIC, QFP-132
文件頁數(shù): 39/153頁
文件大?。?/td> 838K
代理商: AM79C974KCW
P R E L I M I N A R Y
AMD
39
Am79C974
Target Abort
Figure 13 shows a target abort sequence. The target as-
serts
DEVSEL
for one clock. It then deasserts
DEVSEL
and asserts
STOP
on clock 4. A target can use the target
abort sequence to indicate that it cannot service the data
transfer and that it does not want the transaction to be
retried. Additionally, the Am79C974 controller cannot
make any assumption about the success of the previous
data transfers in the current transaction. The
Am79C974 controller terminates the current transfer
with the deassertion of
FRAME
on clock 5 and one clock
cycle later with the deassertion of
IRDY
. It finally re-
leases the bus on clock 6.
Since data integrity is not guaranteed, the Am79C974
controller cannot recover from a target abort event. For
Ethernet, the Am79C974 controller will reset all CSR
and BCR locations to their H_RESET values. Any on-
going network activity will be stopped immediately. The
PCI configuration registers will not be cleared. For
SCSI, when target aborts,
INTA
will not be asserted, but
the ABORT bit (bit 2 of the DMA status register at offset
54h), is set. For either Ethernet or SCSI a target abort
causes RTABORT (bit 12) of the status register in the
appropriate PCI configuration space to beset.
18681A-17
FRAME
CLK
AD
IRDY
TRDY
C/
BE
DEVSEL
REQ
GNT
1
2
3
4
5
6
DATA
0000
0111
PAR
PAR
PAR
DEVSEL
is sampled by the Am79C974 controller.
STOP
ADDR
Figure 13. Target Abort
相關(guān)PDF資料
PDF描述
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
AM79C973KCW PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
AM79C975KCW PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
AM79C973VCW 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
AM79C975 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet⑩-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY
AM79C975BKC\\W 制造商:Advanced Micro Devices 功能描述:
AM79C975BKC\W 制造商:Advanced Micro Devices 功能描述:
AM79C975BKD\\W 制造商:Advanced Micro Devices 功能描述:
AM79C975BKD\W 制造商:Advanced Micro Devices 功能描述:PCnet-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY 制造商:AMD (Advanced Micro Devices) 功能描述:PCnet-FAST III Single-Chip 10/100 Mbps PCI Ethernet Controller with Integrated PHY