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gogogo
Joined: 22 Jan 2005
Posts: 43
Helped: 1
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 22 Feb 2005 8:11 bus holder |
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who can tell me?
what is bus holder? and what is it used to do?
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arunragavan
Joined: 01 Jul 2004
Posts: 487
Helped: 21
Location: India
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22 Feb 2005 8:26 bus keeper |
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We have a bus holder :
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a
Pin I should be model wize an inout, so vital needs tipd_i statement.
But in sysnopys we need to declare this as input because there is no function
associated with this pin. Plus there is no timing for this cell.
Actually, it is not true to say that there is no functionality
associated with the pin, although synopsys may think that there is
not.
The work arround we are using is to describe in synopsys the I pin as input,
to have a vhdl model for the cell not a vital model
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nand_gates
Joined: 19 Jul 2004
Posts: 907
Helped: 120
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22 Feb 2005 10:56 ergonomic bus holder |
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1.Bus holder is a weak latch circuit which hold last value on a tri state bus. It looks
like two invertors connected back to back.
2. It is used to prevent CMOS gate inputs to get floating which may destroy the CMOS
gate itself!
For more info on this please refet to ASIC book by Smith.
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Google
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22 Feb 2005 10:56 Ads |
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gogogo
Joined: 22 Jan 2005
Posts: 43
Helped: 1
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23 Feb 2005 9:51 bus-holder |
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and can it reduce the power consumption of system?
why?
Added after 13 minutes:
which chaper of ASIC book by Smith introduce bus holder?
i can not find it!
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gogogo
Joined: 22 Jan 2005
Posts: 43
Helped: 1
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27 Feb 2005 13:20 tri state bus holder |
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| o,,, i got it, bus holder---another name is bus keeper, asic book by smith just introduce it simply.
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xiaolongbao
Joined: 22 Jan 2005
Posts: 16
Helped: 1
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18 Mar 2005 6:23 bus holder circuit |
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yes busholder or another name is bus keeper
is just to hold last step data of the memory.
<<asic book>> simply intruduce it
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