MPC563XM Reference Manual, Rev. 1
Freescale Semiconductor
683
Preliminary—Subject to Change Without Notice
Figure 22-55. OPWFMB Mode with Active Output Disable
Note that the output disable has a synchronous operation, meaning that the assertion of the Output Disable
input pin causes the channel output flip-flop to transition to EDPOL at the next system clock cycle. If the
Output Disable input is deasserted the output pin transition at the following A1 or B1 match.
it is assumed that the Output Disable input is enabled and selected for the Channel. Please,
refer to
Section 22.4.2.8, “eMIOS200 UC Control Register (EMIOSC[n])
for a detailed description about
the ODIS and ODISSL bits, respectively enable and selection of the Output Disable inputs.
The FORCMA and FORCMB bits allow the software to force the output flip-flop to the level
corresponding to a match on comparators A or B respectively. Similarly to a B1 match FORCMB sets the
internal counter to $1. The FLAG bit is not set by the FORCMA or FORCMB bits being asserted.
describes the generation of 100% and 0% duty cycle signals. It is assumed EDPOL =0 and
the resultant prescaler value is 1. Initially A1=$8 and B1=$8. In this case, B1 match has precedence over
A1 match, thus the output flip-flop is set to the complement of EDPOL bit. This cycle corresponds to a
100% duty cycle signal. The same output signal can be generated for any A1 value greater or equal to B1.
EDPOL = 0
cycle n
cycle n+1
cycle n+2
A1 value
B1 value
B2 value
$000008
$000002
$000006
$000008
$000001
internal counter
$000004
$000006
MODE
[6]
= 1
A2 value $000002
$000004
$000006
$000002
$000004
$000006
$000008
$000006
Output pin
write to B2
write to A2
write to A2
Match A1
Match A1
Match B1
Match B1
Match B1
due to B1 match cycle n-1
FLAG set event
Output Disable
FLAG pin/register
Prescaler ratio = 1
FLAG set event