MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
17-28 Freescale Semiconductor
NOTE
The GPIO modes provided in the eMIOS are particularly useful as interim
modes when certain other eMIOS modes are being dynamically configured
and enabled or disabled during the execution of the application. For normal
GPIO function on the eMIOS pins, it is recommended that the SIU be used
to configure those pins as system GPIO. See Section 6.2.1.3,
“General-Purpose I/O Pins (GPIO[0:210]).
17.4.4.4.2 Single Action Input Capture Mode (SAIC)
In SAIC mode, when a triggering event occurs on the input pin, the value on the selected time base is
captured into register A2. At the same time, the FLAG bit is set to indicate that an input capture has
occurred. Register EMIOS_CADRn returns the value of register A2.
The input capture is triggered by a rising, falling or either edges in the input pin, as configured by EDPOL
and EDSEL bits in EMIOS_CCRn.
Figure 17-15 shows how the unified channel can be used for input capture.
Figure 17-15. Single Action Input Capture Example
17.4.4.4.3 Single Action Output Compare Mode (SAOC)
In SAOC mode a match value is loaded in register A2 and then transferred to register A1 to be compared
with the selected time base. When a match occurs, the EDSEL bit selects if the output flip-flop is toggled
or if the value in EDPOL is transferred to it. At the same time, the FLAG bit is set to indicate that the output
compare match has occurred. Writing to register EMIOS_CADRn stores the value in register A2 and
reading to register EMIOS_CADRn returns the value of register A1.
Table 17-15. Mode of Operation: SAIC Mode
MODE[0:6] Unified Channel Mode of Operation
0b0000010 Single Action Input Capture Mode
Table 17-16. Mode of Operation: SAOC Mode
MODE[0:6] Unified Channel Mode of Operation
0b0000011 Single Action Output Compare Mode
Selected
Counter Bus
FLAG
Set Event
Edge Detect Edge Detect Edge Detect
Captured A2
Val ue
2
0xxxxxxx 0x001000 0x001250 0x0016A0
Notes:
1
2
Input Signal
1
0x000500 0x001000 0x001100 0x001250 0x001525 0x0016A0
After input filter.
Reading EMIOS_CADRn returns the value of A2.
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