Configure PCA Module
ECOMn CAPPn CAPNn MATn
TOGn PWMn ECCFn
Module function
0
0
1
0
0
0
0
0
0
0
0
0
No operation
X
X
16-bit capture by a positive-edge trigger on
CEXn
X
X
1
1
1
0
1
0
0
0
1
1
0
0
0
0
0
1
1
0
0
0
0
1
0
0
0
0
0
1
X
X
X
X
0
16-bit capture by a negative trigger on CEXn
16-bit capture by a transition on CEXn
16-bit Software Timer
16-bit High Speed Output
8-bit PWM
PCA Capture Mode
To use one of the PCA modules in the capture mode, one or both of bits CAPPn and CAPNn
in SFR CCAPMn should be set. The external CEXn input for the module is sampled for a
transition. When a valid transition occurs, the PCA hardware loads the value of the PCA
counter register (CH and CL) into the module’s capture registers (CCAPnH and CCAPnL). If
the bit CCFn for the module in the SFR CCON and the bit ECCFn in the SFR CCAPMn are
set then an interrupt will be generated.
-
CF
CR
-
CCF3 CCF2 CCF1 CCF0
CCON
PCA
interrupt
CH
CL
CAPTURE
CEXn
CCAPnH CCAPnL
ECOMn
CAPPn
CAPNn
MATn
TOGn
PWMn
ECCFn
-
MDnCON
0
0
0
0
PCA Capture Mode
16-bit Software Timer Mode
The PCA modules can be used as software timers by setting both the ECOMn and MATn bits
in the CCAPMn register. The PCA timer will be compared to the module’s capture registers,
and when a match occurs an interrupt will be generated if the CCFn and ECCFn bits for the
module are both set.
MEGAWIN
MPC82x54A Data Sheet
43
MEGAWIN [ MEGAWIN TECHNOLOGY CO., LTD ]
