MC68HC908RF2 Datasheet, PDF (246/254 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Preliminary Electrical Specifications
17.10 Control Timing
Characteristic
Symbol
Min
Max
Unit
Bus operating frequency
V_DD = 3.0 V ± 10%
V_DD = 2.0 V ± 10%
RESET pulse width low
IRQ interrupt pulse width low (edge-triggered)
IRQ interrupt pulse period
f_Bus
32 k
4.0 M
Hz
32 k
2.0 M
t_RL
1.5
—
t_cyc
t_ILHI
1.5
—
t_cyc
t_ILIL
Note 4
—
t_cyc
16-bit timer (Note 2)
Input capture pulse width (Note 3)
Input capture period
Input clock pulse width
t_TH, t_TL
2
—
t_cyc
t_TLTL
Note 4
—
t_cyc
t_TCH, t_TCL ^(1/fOP^{) + 5}
—
ns
Notes:
1. V_DD = 1.8 V to 3.3 V, V_SS = 0 Vdc, T_A = –40^oC to +85^oC, unless otherwise noted
2. The 2-bit timer prescaler is the limiting factor in determining timer resolution.
3. Refer to Table 15-3. Mode, Edge, and Level Selection and supporting note.
4. The minimum period t_TLTL or t_ILIL should not be less than the number of cycles it takes to execute the capture interrupt
service routine plus 2 t_cyc.
17.11 Internal Oscillator Characteristics
Characteristic⁽¹⁾
Symbol
Min
Typ
Max
Unit
Internal oscillator base frequency without
trim^{(2) (3)}
f_INTOSC
230.4
307.2
384.0
kHz
Internal oscillator base frequency
with trim^{(2) (3)}
f_INTOSC(I)
291.8
307.2
322.6
kHz
Internal oscillator multiplier⁽⁴⁾
N
1
—
127
—
External clock option⁽⁵⁾
3 V ± 10%
2 V ± 10%
f_EXTOSC
128 k
—
128 k
—
16
MHz
8
1. V_DD = 1.8 V to 3.3 V, V_SS = 0 Vdc, T_A = –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. f_Bus = (f_INTOSC / 4) x (internal oscillator multiplier)
4. Multiplier must be chosen to limit the maximum bus frequency to the maximum listed in 17.10 Control Timing.
5. No more than 10% duty cycle deviation from 50%
Advance Information
246
Preliminary Electrical Specifications
MC68HC908RF2 — Rev. 1
MOTOROLA