"John_H" <newsgroup@johnhandwork.com> wrote in message
news:88fb24da-8f2b-4f3f-833a-059b79fc0eae@k30g2000hse.googlegroups.com...
> fmostafa wrote:
>> hi all;
>>
>> I am using Edk to create IP peripheral which contains RD and WR
>> Fifos. My question is, if the required data to be written to the read
>> fifo is undefined it will not be stored in the fifo or what.
>>
>> fatma
>
> Please define undefined data, electrically.
??
Undefined data is not defined, by definition.
It is a simulation state, not an electrical state.
JTW
Reply by Peter Alfke●August 1, 20082008-08-01
On Aug 1, 7:05=A0am, fmostafa <fatma.abouele...@ugent.be> wrote:
> hi all;
>
> I am using Edk =A0to create =A0IP =A0peripheral which contains RD and WR
> Fifos. My question is, =A0if the required data to be written to the read
> fifo is undefined =A0it will not be stored in the fifo or what.
>
> fatma
Fatma, a FIFO is (conceptually) very simple: You store your data word
by enabling the write clock, and you pull the data word out in the
same sequence that you wrote it, by enabling the read clock. Use free-
running clocks, and manipulate the Clock Enable. Remember: Data is
never undefined, it is what it is, 0 or 1.
Peter Alfke
Reply by John_H●August 1, 20082008-08-01
fmostafa wrote:
> hi all;
>
> I am using Edk to create IP peripheral which contains RD and WR
> Fifos. My question is, if the required data to be written to the read
> fifo is undefined it will not be stored in the fifo or what.
>
> fatma
Please define undefined data, electrically.
Reply by Mike Lewis●August 1, 20082008-08-01
"fmostafa" <fatma.abouelella@ugent.be> wrote in message
news:7dd39237-2837-4722-b062-6a849321cfef@k37g2000hsf.googlegroups.com...
> hi all;
>
> I am using Edk to create IP peripheral which contains RD and WR
> Fifos. My question is, if the required data to be written to the read
> fifo is undefined it will not be stored in the fifo or what.
>
> fatma
If you write undefined data to a fifo .. that's what will be stored in the
fifo .. undefined data.
If you don't want this to be stored ... don't assert the fifo push signal.
Mike
Reply by fmostafa●August 1, 20082008-08-01
hi all;
I am using Edk to create IP peripheral which contains RD and WR
Fifos. My question is, if the required data to be written to the read
fifo is undefined it will not be stored in the fifo or what.
fatma