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ManualsBrandsSTMICROELECTRONICS ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller PQFP 144 16-Bit 40 MHz I/O number 111
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ST10F269
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21.4.3 - Clock Generation Modes
The Table 44 associates the combinations of these three bits with the respective clock generation mode.
Notes: 1. The external clock input range refers to a CPU clock range of 1...40MHz.
2. The maximum input frequency depends on the duty cycle of the external clock signal.
3. The maximum input frequency is 25MHz when using an external crystal with the internal oscillator; providing that internal serial
resistance of the crystal is less than 40Ω. However, higher frequencies can be applied with an external clock source on pin XTAL1,
but in this case, the input clock signal must reach the defined levels V
IL
and V
IH2.
.
.
Notes: 1. The external clock input range refers to a CPU clock range of 1...32MHz.
2. The maximum input frequency depends on the duty cycle of the external clock signal.
3. The maximum input frequency is 32MHz when using an external crystal with the internal oscillator; providing that internal serial
resistance of the crystal is less than 40Ω. However, higher frequencies can be applied with an external clock source on pin XTAL1,
but in this case, the input clock signal must reach the defined levels V
IL
and V
IH2.
.
Table 44 : CPU Frequency Generation (PQFP144 devices)
P0H.7 P0H.6 P0H.5
CPU Frequency f
CPU
= f
XTAL
x F
External Clock Input Range
1
Notes
111
f
XTAL
x 4 2.5 to 10MHz
Default configuration
110
f
XTAL
x 3 3.33 to 13.33MHz
101
f
XTAL
x 2 5 to 20MHz
100
f
XTAL
x 5 2 to 8MHz
011
f
XTAL
x 1
1 to 40MHz
Direct drive
2
010
f
XTAL
x 1.5 6.66 to 26.66MHz
001
f
XTAL
x 0.5
2 to 80MHz
CPU clock via prescaler
3
000
f
XTAL
x 2.5 4 to 16MHz
Table 45 : CPU Frequency Generation (TQFP144 devices)
P0H.7 P0H.6 P0H.5
CPU Frequency f
CPU
= f
XTAL
x F
External Clock Input Range
1
Notes
111
f
XTAL
x 4
2.5 to 8MHz Default configuration
110
f
XTAL
x 3
3.33 to 10.67MHz
101
f
XTAL
x 2
5 to 16MHz
100
f
XTAL
x 5
2 to 6.4MHz
011
f
XTAL
x 1
1 to 32MHz
Direct drive
2
010
f
XTAL
x 1.5
6.67 to 21.33MHz
001
f
XTAL
x 0.5
2 to 64MHz
CPU clock via prescaler
3
000
f
XTAL
x 2.5
4 to 12.8MHz