st72f321r STMicroelectronics, st72f321r Datasheet - Page 147

• Manufacturer Part Number: st72f321r
• Description: 64/44-pin 8-bit Mcu With 32 To 60k Flash/rom, Adc, Five Timers, Spi, Sci, I2c Interface
• Manufacturer: STMicroelectronics

12.5 CLOCK AND TIMING CHARACTERISTICS
Subject to general operating conditions for V
12.5.1 General Timings
12.5.2 External Clock Source
Figure 77. Typical Application with an External Clock Source
Notes:
1. Data based on typical application software.
2. Time measured between interrupt event and interrupt vector fetch. t
the current instruction execution.
3. Data based on design simulation and/or technology characteristics, not tested in production.
t
t
Symbol
Symbol
w(OSC1H)
V
w(OSC1L)
V
t
t
t
r(OSC1)
f(OSC1)
c(INST)
OSC1H
t
OSC1L
v(IT)
I
L
V
V
Instruction cycle time
Interrupt reaction time
t
OSC1 input pin high level voltage
OSC1 input pin low level voltage
OSC1 high or low time
OSC1 rise or fall time
OSC1 Input leakage current
OSC1H
OSC1L
v(IT)
EXTERNAL
CLOCK SOURCE
= t
c(INST)
Parameter
Parameter
+ 10
t
r(OSC1)
3)
2)
3)
t
f(OSC1)
OSC2
OSC1
90%
f
f
see
V
DD
CPU
CPU
SS
10%
, f
Figure 77
=8MHz
=8MHz
V
CPU
IN
Conditions
Conditions
, and T
V
DD
t
Not connected internally
w(OSC1H)
A
.
c(INST)
I
is the number of t
L
t
w(OSC1L)
1.25
Min
250
10
V
2
Min
V
DD
5
SS
-1
f
OSC
Typ
ST72XXX
375
Typ
3
CPU
1)
cycles needed to finish
1500
Max
2.75
V
Max
12
22
V
SS
15
±1
DD
+1
ST72321
147/189
Unit
Unit
t
t
CPU
CPU
ns
ns
V
s
A