Autor: Michal Letowski (milet_at_geocities.com)
Data: Tue 26 Mar 2002 - 22:42:51 MET
Użytkownik "Pat." <dc8_at_wp.pl> napisał w wiadomości
news:a7p7pg$t17$1_at_news.tpi.pl...
> co to jest w Biosie :Differential Current -na jaką
> wartość ma być ustawione x4 ,x5, x6, x7,??
> Procek P4 2A 2Ghz
> Prosze o odpowiedz
>
On the P4 platform, the host clocks (CPU clocks) are different from earlier
Intel platforms. Instead of acting as a voltage source with a set voltage
swing, it acts as a current source and injects a set amount of current into
the transmission line. You have to use parallel termination on the line to
set the voltage swing.
The "differential current" option in the Abit bios just lets you fiddle with
the amount of current injected into the line (by mulitiplying some set
value, which they don't tell you). This effectively lets you change the
voltage swing of the clocks.
The Abit TH7-II manual says "This option allows you to select the current
multiple of CPU clock. The options are: 4x, 6x, 5x, 7x. The default setting
is 6x." (Bad English theirs).
They call it "differential current" because the clocks are differential.
That means instead of a single clock, you have a CLK and CLK#. One is going
high while one is going low (for those who care, they operate in odd-mode
differential signalling). That means when CLK is on, CLK# is off. Thus,
differential current.
Michal Letowski
To archiwum zostało wygenerowane przez hypermail 2.1.7 : Wed 19 May 2004 - 00:33:16 MET DST