mpc82x52a Megawin Technology, mpc82x52a Datasheet - Page 44

• Manufacturer Part Number: mpc82x52a
• Description: 8-bit Micro-controller
• Manufacturer: Megawin Technology

44
High Speed Output Mode
In this mode the CEXn output (port latch) associated with the PCA module will toggle each
time a match occurs between the PCA counter and the module’s capture registers. To activate
this mode the TOGn, MATn, and ECOMn bits in the SFR CCAPMn must be set.
Pulse Width Modulator Mode
All of the PCA modules can be used as PWM outputs. The frequency of the output depends
on the PCA counter. All of the modules will have the same frequency of output because they
all share the PCA counter. The duty cycle of each module is independently variable using the
module’s capture register CCAPnL[7:0] and bits EPCnL in SFR PCAPWMn. When the value
of the SFR CL is less than the value in the module’s {EPCnL, CCAPnL [7:0]}, the output will
be low. When it is equal to or greater than, the output will be high. When CL overflows from
FF
That allows smoothly updating the PWM duty without glitches. The bits PWMn and ECOMn
bits in the CCAPMn must be set to enable the PWM mode.
SFR: PCAPWM0 (PCA PWM Mode Auxiliary Register 0 )
SFR: PCAPWM1 (PCA PWM Mode Auxiliary Register 1)
H
EPCnL: = concatenated with CCAPnL, used to control the duty of the PWM output
EPCnH: = Reloaded value of EPCnL while CL [7:0] counts from FF
to 00
Bit-7
Bit-7
-
-
H
The bit EPCnL is going to be combined with CCAPnL to form a 9-bit data which will
be compared with PCA counter low byte CL, so to determine the duty of the module-n’s PWM
output.
, {EPCnL, CCAPnL [7:0]} is reloaded with the value in {EPCnH, CCAPnH [7:0]}.
Bit-6
Bit-6
If
else
-
-
{CL[7:0]} < { EPCnL, CCAPnL[7:0]} , PWM output LOW
Bit-5
Bit-5
-
-
MPC82x52A Data Sheet
Bit-4
Bit-4
-
-
Bit-3
Bit-3
-
-
PWM output HIGH
Bit-2
Bit-2
H
-
-
to 00
H
EPC1H
EPC0H
Bit-1
Bit-1
MEGAWIN
EPC1L
EPC0L
Bit-0
Bit-0