Datasheet
2010 Microchip Technology Inc. DS70138G-page 81
dsPIC30F3014/4013
12.0 INPUT CAPTURE MODULE
This section describes the input capture module and
associated operational modes. The features provided
by this module are useful in applications requiring fre-
quency (period) and pulse measurement. Figure 12-1
depicts a block diagram of the input capture module.
Input capture is useful for such modes as:
• Frequency/Period/Pulse Measurements
• Additional Sources of External Interrupts
The key operational features of the input capture
module are:
• Simple Capture Event mode
• Timer2 and Timer3 mode selection
• Interrupt on input capture event
These operating modes are determined by setting the
appropriate bits in the ICxCON register (where
x = 1,2,...,N). The dsPIC DSC devices contain up to 8
capture channels (i.e., the maximum value of N is 8).
The dsPIC30F3014 device contains 2 capture
channels while the dsPIC30F4013 device contains
4 capture channels.
12.1 Simple Capture Event Mode
The simple capture events in the dsPIC30F product
family are:
• Capture every falling edge
• Capture every rising edge
• Capture every 4th rising edge
• Capture every 16th rising edge
• Capture every rising and falling edge
These simple Input Capture modes are configured by
setting the appropriate bits, ICM<2:0> (ICxCON<2:0>).
12.1.1 CAPTURE PRESCALER
There are four input capture prescaler settings speci-
fied by bits, ICM<2:0> (ICxCON<2:0>). Whenever the
capture channel is turned off, the prescaler counter is
cleared. In addition, any Reset clears the prescaler
counter.
FIGURE 12-1: INPUT CAPTURE MODE BLOCK DIAGRAM
Note: This data sheet summarizes features of
this group of dsPIC30F devices and is not
intended to be a complete reference
source. For more information on the CPU,
peripherals, register descriptions and
general device functionality, refer to the
“dsPIC30F Family Reference Manual”
(DS70046).
ICxBUF
Prescaler
ICx pin
ICM<2:0>
Mode Select
3
Note: Where ‘x’ is shown, reference is made to the registers or bits associated to the respective input capture
channels, 1 through N.
10
Set Flag
ICxIF
ICTMR
T2_CNT
T3_CNT
Edge
Detection
Logic
Clock
Synchronizer
1, 4, 16
From GP Timer Module
16 16
FIFO
R/W
Logic
ICI<1:0>
ICBNE, ICOV
ICxCON
Interrupt
Logic
Set Flag
ICxIF
Data Bus