MC68HC908EY16 Datasheet, PDF (244/278 Pages) Motorola, Inc – Microcontrollers

Electrical Specifications
20.6 Control Timing
Characteristic⁽¹⁾
Symbol
Min
Max
Unit
Frequency of operation⁽²⁾
Crystal option (EXTSLOW = 1)
Crystal option (EXTSLOW = 0)
External clock option⁽³⁾
f_osc
32
100
kHz
1
8
MHz
dc⁽⁴⁾
32
MHz
Internal operating frequency
f_op
—
8
MHz
Internal clock period (1/f_OP)
t_cyc
125
—
ns
RST input pulse width low⁽⁵⁾
t_IRL
50
—
ns
IRQ interrupt pulse width low⁽⁶⁾
(edge-triggered)
t_ILIH
50
—
ns
IRQ interrupt pulse period
t_ILIL
Note 8
—
t_cyc
16-bit timer⁽⁷⁾
Input capture pulse width
Input capture period
t_TH,t_TL
t_TLTL
Note 8
—
—
ns
t_cyc
1. V_SS = 0 Vdc; timing shown with respect to 20% V_DD and 70% V_SS unless otherwise noted.
2. See Chapter 8 Internal Clock Generator (ICG) Module for more information.
3. No more than 10% duty cycle deviation from 50%
4. Some modules may require a minimum frequency greater than dc for proper operation. See appropriate table for this
information.
5. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset.
6. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to be recognized.
7. Minimum pulse width is for guaranteed interrupt. It is possible for a smaller pulse width to be recognized.
8. The minimum period, t_ILIL or t_TLTL, should not be less than the number of cycles it takes to execute the interrupt service
routine plus t_cyc.
20.7 Internal Oscillator Characteristics
Characteristic⁽¹⁾
Symbol
Min
Typ
Max
Unit
Internal oscillator base frequency^{(2), (3)}
f_INTOSC
230.4
307.2
384
kHz
Internal oscillator tolerance
f_{OSC_TOL}
–25
—
+25
%
Internal oscillator multiplier⁽⁴⁾
N
1
—
127
—
1. V_DD = 4.5 to 5.5 Vdc, V_SS = 0 Vdc, T_A = –40°C to +135°C, 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 N when internal clock source selected
4. Multiplier must be chosen to limit the maximum bus frequency of 8 MHz for 4.5-V operation.
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
244
Freescale Semiconductor