MC68HC908GR16A Datasheet, PDF (253/270 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

20.7 5.0-Volt Control Timing
5.0-Volt Control Timing
Characteristic⁽¹⁾
Symbol
Min
Max
Frequency of operation
Crystal option
External clock option⁽²⁾
f_OSC
1
8
dc
32
Internal operating frequency
Internal clock period (1/f_OP)
RST input pulse width low
IRQ interrupt pulse width low (edge-triggered)
IRQ interrupt pulse period
f_OP (f_Bus)
—
8
t_CYC
125
—
t_RL
50
—
t_ILIH
50
—
t_ILIL
Note⁽³⁾
—
1. V_SS = 0 Vdc; timing shown with respect to 20% V_DD and 70% V_DD unless otherwise noted.
2. No more than 10% duty cycle deviation from 50%.
3. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 t_CYC.
Unit
MHz
MHz
ns
ns
ns
t_CYC
20.8 3.3-Volt Control Timing
Characteristic⁽¹⁾
Symbol
Min
Max
Frequency of operation
Crystal option
External clock option⁽²⁾
f_OSC
1
8
dc
16
Internal operating frequency
Internal clock period (1/f_OP)
RST input pulse width low
IRQ interrupt pulse width low (edge-triggered)
IRQ interrupt pulse period
f_OP (f_Bus)
—
4
t_CYC
250
—
t_RL
125
—
t_ILIH
125
—
t_ILIL
Note⁽³⁾
—
1. V_SS = 0 Vdc; timing shown with respect to 20% V_DD and 70% V_DD unless otherwise noted.
2. No more than 10% duty cycle deviation from 50%.
3. The minimum period is the number of cycles it takes to execute the interrupt service routine plus 1 t_CYC.
Unit
MHz
MHz
ns
ns
ns
t_CYC
t_RL
RST
t_ILIL
t_ILIH
IRQ
Figure 20-1. RST and IRQ Timing
MC68HC908GR16A Data Sheet, Rev. 1.0
Freescale Semiconductor
253