MB90520B Datasheet, PDF (74/104 Pages) Fujitsu Component Limited. – 16-bit Microcontroller

MB90520B Series
21. Clock Monitor Function
The clock monitor function outputs the machine clock divided by a specified amount to the clock monitor pin
(CKOT) .
• Clock monitor functions
Function
Output frequency
Machine clock divided by 2 to 32 (8 settings available)
Interrupts
None
EI²OS support
Not supported by the extended intelligent I/O service (EI²OS) .
• Output frequency of the clock monitor function
FRQ2 to FRQ0 Machine Clock
Bits
Divide Ratio
When φ = 16 MHz
Period Frequency
000B
φ/2¹
125 ns
8 MHz
001B
φ/2²
250 ns
4 MHz
010B
φ/2³
500 ns
2 MHz
011B
φ/2⁴
1.0 µs
1 MHz
100B
φ/2⁵
2.0 µs
500 kHz
101B
φ/2⁶
4.0 µs
250 kHz
110B
φ/2⁷
8.0 µs
125 kHz
111B
φ/2⁸
16.0 µs 62.5 kHz
When φ = 8 MHz
Period Frequency
250 ns
4 MHz
500 ns
2 MHz
1.0 µs
1 MHz
2.0 µs
500 kHz
4.0 µs
250 kHz
8.0 µs
125 kHz
16.0 µs 62.5 kHz
32.0 µs 31.25 kHz
When φ = 4 MHz
Period Frequency
500 ns
2 MHz
1.0 µs
1 MHz
2.0 µs
500 kHz
4.0 µs
250 kHz
8.0 µs
125 kHz
16.0 µs 62.5 kHz
32.0 µs 31.25 kHz
64.0 µs 15.625 kHz
• Block diagram
Count
φ
Prescaler
clock
Pin
selector
CKOT
Clock output enable
3
register (CLKR)
⎯ ⎯ ⎯ ⎯ CKEN FRQ2 FRQ1 FRQ0
Output enable
⎯ : Undefined
φ : Machine clock frequency
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DS07-13707-5E