參數(shù)資料
型號: Z53C80SCSI
廠商: ZiLOG, Inc.
英文描述: SMALL COMPUTER SYSTEM INTERFACE (SCSI)
中文描述: 小型計(jì)算機(jī)系統(tǒng)接口(SCSI)
文件頁數(shù): 14/40頁
文件大小: 447K
代理商: Z53C80SCSI
14
Z53C80 SCSI
PS97SCC0200
Z
ILOG
FUNCTIONAL DESCRIPTION
(Continued)
Figure 16. Current SCSI Bus Status Register
End of Process (EOP) Interrupt.
An End Of Process
signal (EOP) which occurs during a DMA transfer (DMA
Mode True) will set the End of DMA Status bit (Bus and
Status Register bit 7) and will optionally generate an
interrupt if Enable EOP Interrupt bit (Mode Register, bit 3)
is True. The /EOP pulse will not be recognized (End of DMA
bit set) unless /EOP, /DACK, and either /RD or /WR are
concurrently active for at least 50 ns. DMA transfers can
still occur if /EOP was not asserted at the correct time. This
interrupt is disabled by resetting the Enable EOP Interrupt
bit.
The proper values for the Bus and Status Register and the
Current SCSI Bus Status Register for this interrupt are
shown in Figures 17 and 18.
Figure 17. Bus and Status Register
Figure 18. Current SCSI Bus Status Register
The End of DMA bit is used to determine when a block
transfer is complete. Receive operations are complete
when there is no data left in the chip and no additional
handshakes occurring. The only exception to this is
receiving data as an Initiator and the Target opts to send
additional data for the same phase. In this /REQ goes
active and the new data is present in the Input Data
Register. Since a phase-mismatch interrupt will not occur,
/REQ and /ACK need to be sampled to determine that the
Target is attempting to send more data.
For send operations, the End of DMA bit is set when the
DMA finishes its transfers, but the SCSI transfer may still be
in progress. If connected as a Target, /REQ and /ACK
should be sampled until both are False. If connected as an
Initiator, a phase change interrupt is used to signal the
completion of the previous phase. It is possible for the
Target to request additional data for the same phase. In
this case, a phase change will not occur and both /REQ
and /ACK are sampled to determine when the last byte was
transferred.
SCSI Bus Reset.
The SCSI generates an interrupt when
the /RST signal transitions to True. The device releases all
bus signals within a bus-clear delay of this transition. This
interrupt also occurs after setting the Assert /RST bit
(Initiator Command Register, bit 7). This interrupt cannot
be disabled. (Note: /RST is not latched in bit 7 of the
Current SCSI Bus Status Register and is not active when
this port is read. For this case, the Bus Reset interrupt is
determined by default.)
The proper values for the Bus and Status Register and the
Current SCSI Bus Status Register are displayed in Figures
19 and 20, respectively.
D7
D0
/DBP
/SEL
I//O
C//D
/MSG
/REQ
/BSY
/RST
0
0
0
X
X
X
0
X
D7
D0
/ACK
/ATN
Busy Error
Phase Match
Interrupt Request Active
Parity Error
DMA Request
End of DMA
1
0
0
1
0
0
0
X
D7
D0
/DBP
/SEL
I//O
C//D
/MSQ
/REQ
/BSY
/RST
0
1
1
X
X
X
0
X
相關(guān)PDF資料
PDF描述
Z54122 RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
Z5U0603 ceramic chip capacitors
Z5U0805 ceramic chip capacitors
Z5U1206 ceramic chip capacitors
Z5U1210 ceramic chip capacitors
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
Z53E11 制造商:OMRON INDUSTRIAL AUTOMATION 功能描述:E5M Operation Manual DX CODE ZA
Z53RD431 制造商:HVCA & CKE 功能描述:Varistor, MO, 430V, 50000A, 7000pF
Z540 制造商:INTEL 制造商全稱:Intel Corporation 功能描述:Intel Atom Processor
Z540-TRACEABLE-W/DATA 功能描述:手持示波器 NIST-CAL-CERT TRACEABLE W/DATA RoHS:否 制造商:Fluke 帶寬:200 MHz 采樣比:2.5 GS/s 顯示器類型:153 mm Full Color LCD 設(shè)備類型:Oscilloscopes
Z54122 制造商:未知廠家 制造商全稱:未知廠家 功能描述:RETRIGGERABLE MONOSTABLE MULTIVIBRATOR