2
1
GP [ ] as input
n m
GP [ ] as input
n m
4
3
2
1
GP [ ] as output
n m
OMAP-L137
SPRS563G – SEPTEMBER 2008 – REVISED JUNE 2014
www.ti.com
6.8.2
GPIO Peripheral Input/Output Electrical Data/Timing
Table 6-11. Timing Requirements for GPIO Inputs
(1)
(see
Figure 6-10
)
No.
PARAMETER
MIN
MAX
UNIT
1
t
w(GPIH)
Pulse duration, GP
n[m]
as input high
2C
(1) (2)
ns
2
t
w(GPIL)
Pulse duration, GP
n[m]
as input low
2C
(1) (2)
ns
(1)
The pulse width given is sufficient to generate a CPU interrupt or an EDMA event. However, if a user wants to have OMAP-L137
recognize the GPIx changes through software polling of the GPIO register, the GPIx duration must be extended to allow OMAP-L137
enough time to access the GPIO register through the internal bus.
(2)
C=SYSCLK4 period in ns.
Table 6-12. Switching Characteristics Over Recommended Operating Conditions for GPIO Outputs
(see
Figure 6-10
)
No.
PARAMETER
MIN
MAX
UNIT
3
t
w(GPOH)
Pulse duration, GP
n[m]
as output high
2C
(1) (2)
ns
4
t
w(GPOL)
Pulse duration, GP
n[m]
as output low
2C
(1) (2)
ns
(1)
This parameter value should not be used as a maximum performance specification. Actual performance of back-to-back accesses of the
GPIO is dependent upon internal bus activity.
(2)
C=SYSCLK4 period in ns.
Figure 6-10. GPIO Port Timing
6.8.3
GPIO Peripheral External Interrupts Electrical Data/Timing
Table 6-13. Timing Requirements for External Interrupts
(1)
(see
Figure 6-11
)
No.
PARAMETER
MIN
MAX
UNIT
1
t
w(ILOW)
Width of the external interrupt pulse low
2C
(1) (2)
ns
2
t
w(IHIGH)
Width of the external interrupt pulse high
2C
(1) (2)
ns
(1)
The pulse width given is sufficient to generate an interrupt or an EDMA event. However, if a user wants to have OMAP-L137 recognize
the GPIO changes through software polling of the GPIO register, the GPIO duration must be extended to allow OMAP-L137 enough
time to access the GPIO register through the internal bus.
(2)
C=SYSCLK4 period in ns.
Figure 6-11. GPIO External Interrupt Timing
78
Peripheral Information and Electrical Specifications
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