Intel 8XC196NT, User Manual

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2-7
ARCHITECTURAL OVERVIEW
Figure 2-4. Internal Clock Phases
The combined period of phase 1 and phase 2 of the internal CLKOUT signal defines the basic
time unit known as a state time or state. Table 2-2 lists state time durations at various frequencies.
The following formulas calculate the frequency of PH1 and PH2 and the duration of a state time
(F
OSC
is the input frequency to the divide-by-two circuit).
Because the device can operate at many frequencies, this manual defines time requirements in
terms of state times rather than specific times. Consult the latest datasheet for AC timing specifi-
cations.
2.5 INTERNAL PERIPHERALS
The internal peripheral modules provide special functions for a variety of applications. This sec-
tion provides a brief description of each peripheral and other chapters describe each one in detail.
Table 2-2. State Times at Various Frequencies
F
OSC
(Frequency Input to the
Divide-by-two Circuit)
State Time
8 MHz 250 ns
12 MHz 167 ns
16 MHz 125 ns
20 MHz 100 ns
PH1
PH2
CLKOUT
1 State Time
Phase 1 Phase 2
XTAL1
A0114-02
1 State Time
Phase 1 Phase 2
PH1 (in MHz)
F
osc
2
-----------
P H 2 (in MHz)
= =
State Time (in seconds)
2
F
osc
-----------
=