NXP Semiconductors MPC5566 - Double-Action Output Compare Mode (DAOC)

Enhanced Modular Input/Output Subsystem (eMIOS)
MPC5566 Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor 17-35
Figure 17-22 describes the A1 and B1 register updates when EMIOS_CADRn and EMIOS_CBDRn read
operations are performed. When an EMIOS_CADRn read occurs the content of A1 is transferred to B1
thus providing coherent data in the A2 and B1 registers. Transfers from B2 to B1 are then blocked until
EMIOS_CBDRn is read. After EMIOS_CBDRn is read, register A1 content is transferred to register B1
and the transfers from B2 to B1 are re-enabled to occur at the transfer edges, which is the leading edge in
the Figure 17-22 example.
Figure 17-22. A1 and B1 Updates at EMIOS_CADR and EMIOS_CBDR Reads
17.4.4.4.6 Double-action Output Compare Mode (DAOC)
The following table lists the double-action output compare mode settings:
In the DAOC mode the leading and trailing edges of the variable pulse-width output are generated by
matches occurring on comparators A and B, respectively.
When the DAOC mode is first selected (coming from GPIO mode) both comparators are disabled.
Comparators A and B are enabled by updating registers A1 and B1 respectively and remain enabled until
a match occurs on that comparator, when it is disabled again. To update registers A1 and B1, a write to A2
and B2 must occur and the EMIOS_CCRn[ODIS] bit must be cleared.
The output flip-flop is set to the value of EMIOS_CCRn[EDPOL] when a match occurs on comparator A
and to the complement of EDPOL when a match occurs on comparator B.
Table 17-19. DAOC Operating Modes
MODE[0:6] Unified Channel DAOC Operating Mode
0b0000110 Double-action output compare (with FLAG set on the second match)
0b0000111 Double-action output compare (with FLAG set on both matches)
0x000500 0x001000 0x001100 0x001250 0x001525 0x0016A0
Selected
counter bus
FLAG
set event
AAA
Captured A2
value
2
0xxxxxxx
Notes:
1
After input filter.
2
Reading EMIOS_CADRn returns the value of A2.
Input signal
1
EDPOL = 1
B1 value
3
0x001525
0xxxxxxx
0xxxxxxx
0x001000 0x001250
Captured B2
value
3
Reading EMIOS_CBDRn returns the value of B1.
0xxxxxxx 0x001000 0x001250
A1 value
Read MTSA[n]
Read MTSB[n]
0x001250
0x001000
0x001000
0x0016A0
0x001100
0x001250