Microchip Technology MA320002 Data Sheet
© 2011 Microchip Technology Inc.
DS61143H-page 107
PIC32MX3XX/4XX
15.0
INPUT CAPTURE
The Input Capture module is useful in applications
requiring frequency (period) and pulse measurement.
The PIC32MX3XX/4XX devices support up to five input
capture channels.
requiring frequency (period) and pulse measurement.
The PIC32MX3XX/4XX devices support up to five input
capture channels.
The Input Capture module captures the 16-bit or 32-bit
value of the selected Time Base registers when an
event occurs at the ICx pin. The events that cause a
capture event are listed below in three categories:
value of the selected Time Base registers when an
event occurs at the ICx pin. The events that cause a
capture event are listed below in three categories:
1.
Simple Capture Event modes
- Capture timer value on every falling edge of
input at ICx pin
- Capture timer value on every rising edge of
input at ICx pin
2.
Capture timer value on every edge (rising and
falling)
falling)
3.
Capture timer value on every edge (rising and
falling), specified edge first.
falling), specified edge first.
4.
Prescaler Capture Event modes
- Capture timer value on every 4th rising edge
of input at ICx pin
- Capture timer value on every 16th rising
edge of input at ICx pin
Each input capture channel can select between one of
two 16-bit timers (Timer2 or Timer3) for the time base,
or two 16-bit timers (Timer2 and Timer3) together to
form a 32-bit timer. The selected timer can use either
an internal or external clock.
two 16-bit timers (Timer2 or Timer3) for the time base,
or two 16-bit timers (Timer2 and Timer3) together to
form a 32-bit timer. The selected timer can use either
an internal or external clock.
Other operational features include:
• Device wake-up from capture pin during CPU
Sleep and Idle modes
• Interrupt on input capture event
• 4-word FIFO buffer for capture values
- Interrupt optionally generated after 1, 2, 3 or
4 buffer locations are filled
• Input capture can also be used to provide
additional sources of external interrupts
FIGURE 15-1:
INPUT CAPTURE BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC32MX3XX/4XX family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 15. “Input
Capture” (DS61122) of the “PIC32
Family Reference Manual”, which is
available from the Microchip web site
(
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 15. “Input
Capture” (DS61122) of the “PIC32
Family Reference Manual”, which is
available from the Microchip web site
(
www.microchip.com/PIC32
).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
available on all devices. Refer to
in
this data sheet for device-specific register
and bit information.
and bit information.
Prescaler
1, 4, 16
Edge Detect
FIFO Control
Interrupt
Event
Generation
ICxBUF<31:16>
Interrupt
Timer3
Timer2
ICxCON
ICI<1:0>
ICx Input
0
1
ICxBUF<15:0>
Data Space Interface
Peripheral Data Bus
C32
ICTMR
ICM<2:0>
FEDGE
FEDGE
ICBNE
ICOV
ICM<2:0>