ST72F324BJ STMICROELECTRONICS [STMicroelectronics], ST72F324BJ Datasheet - Page 74

• Manufacturer Part Number: ST72F324BJ
• Description: 8-bit MCU, 3.8 to 5.5 V operating range with 8 to 32 Kbyte Flash/ROM, 10-bit ADC, 4 timers, SPI, SCI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

On-chip peripherals
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Input capture
In this section, the index, i, may be 1 or 2 because there are two input capture functions in
the 16-bit timer.
The two 16-bit input capture registers (IC1R/IC2R) are used to latch the value of the free
running counter after a transition is detected on the ICAPi pin (see
Table 43.
The ICiR registers are read-only registers.
The active transition is software programmable through the IEDGi bit of Control Registers
(CRi).
Timing resolution is one count of the free running counter: (
Procedure
To use the input capture function select the following in the CR2 register:
●
●
Select the following in the CR1 register:
●
●
When an input capture occurs:
●
●
●
Clearing the Input Capture interrupt request (that is, clearing the ICFi bit) is done in two
steps:
1.
2.
Select the timer clock (CC[1:0]) (see
Select the edge of the active transition on the ICAP2 pin with the IEDG2 bit (the ICAP2
pin must be configured as floating input or input with pull-up without interrupt if this
configuration is available).
Set the ICIE bit to generate an interrupt after an input capture coming from either the
ICAP1 pin or the ICAP2 pin
Select the edge of the active transition on the ICAP1 pin with the IEDG1 bit (the
ICAP1pin must be configured as floating input or input with pull-up without interrupt if
this configuration is available).
ICFi bit is set.
The ICiR register contains the value of the free running counter on the active transition
on the ICAPi pin (see
A timer interrupt is generated if the ICIE bit is set and the I bit is cleared in the CC
register. Otherwise, the interrupt remains pending until both conditions become true.
Reading the SR register while the ICFi bit is set
An access (read or write) to the ICiLR register
Register
Input capture byte distribution
ICiR
Figure
42).
Table
MS byte
ICiHR
49).
f
CPU
/
CC[1:0]).
Figure
LS byte
42).
ICiLR
ST72324B