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MC68HC908RK2 Datasheet, PDF (152/158 Pages) Motorola, Inc – Microcontroller Unit
Electrical Specifications
13.8 Control Timing
Characteristic(1)
Symbol
Min
Max
Unit
Bus operating frequency
VDD = 3.0 V ± 10%
VDD = 2.0 V ± 10%
fBUS
32 k
4.0 M
Hz
32 k
2.0 M
RESET pulse width low
tRL
1.5
—
tcyc
IRQ interrupt pulse width low (edge-triggered)
tILHI
1.5
—
tcyc
IRQ interrupt pulse period
tILIL
Note 4
—
tcyc
16-bit timer(2)
Input capture pulse width(3)
Input capture period
Input clock pulse width
tTH, tTL
2
—
tcyc
tTLTL
Note(4)
—
tcyc
tTCH, tTCL
(1/fOP) + 5
—
ns
1. VDD = 1.8 V to 3.3 V, VSS = 0 Vdc, TA = –40°C to +85°C, unless otherwise noted
2. The 2-bit timer prescaler is the limiting factor in determining timer resolution.
3. Refer to Table 11-3. Mode, Edge, and Level Selection and supporting note.
4. The minimum period tTLTL or tILIL should not be less than the number of cycles it takes to execute the capture interrupt
service routine plus 2 tcyc.
13.9 Internal Oscillator Characteristics
Characteristic(1)
Symbol
Min
Typ
Max
Unit
Internal oscillator base frequency without trim(2) (3)
fINTOSC
230.4
307.2
384.0
kHz
Internal oscillator base frequency with trim(2) (3)
fINTOSC(I)
301.1
307.2
313.3
kHz
Internal oscillator multiplier(4)
N
1
—
127
—
External clock option(5)
3 V ± 10%
2 V ± 10%
fEXTOSC
128 k
—
128 k
—
16
MHz
8
1. VDD = 1.8 V to 3.3 V, VSS = 0 Vdc, TA = –40 oC to +85 oC, unless otherwise noted
2. Internal oscillator is selectable through software for a maximum frequency,. Actual frequency will be multiplier (N) x base
frequency.
3. fBUS = (fINTOSC / 4) x (internal oscillator multiplier)
4. Multiplier must be chosen to limit the maximum bus frequency to the maximum listed in 13.8 Control Timing.
5. No more than 10% duty cycle deviation from 50%
MC68HC908RK2 Data Sheet, Rev. 5.1
152
Freescale Semiconductor