C8051F02X Datasheet, PDF (252/272 Pages) Silicon Laboratories – 8K ISP FLASH MCU Family

C8051F020/1/2/3
23.2. Capture/Compare Modules
Each module can be configured to operate independently in one of six operation modes: Edge-triggered Capture,
Software Timer, High Speed Output, Frequency Output, 8-Bit Pulse Width Modulator, or 16-Bit Pulse Width Modu-
lator. Each module has Special Function Registers (SFRs) associated with it in the CIP-51 system controller. These
registers are used to exchange data with a module and configure the module's mode of operation.
Table 23.2 summarizes the bit settings in the PCA0CPMn registers used to select the PCA0 capture/compare mod-
ule’s operating modes. Setting the ECCFn bit in a PCA0CPMn register enables the module's CCFn interrupt. Note:
PCA0 interrupts must be globally enabled before individual CCFn interrupts are recognized. PCA0 interrupts are glo-
bally enabled by setting the EA bit (IE.7) and the EPCA0 bit (EIE1.3) to logic 1. See Figure 23.3 for details on the
PCA interrupt configuration.
Table 23.2. PCA0CPM Register Settings for PCA Capture/Compare Modules
PWM16 ECOM CAPP CAPN MAT TOG PWM ECCF Operation Mode
X
X
1
0
0
0
0
X
Capture triggered by positive edge on
CEXn
X
X
0
1
0
0
0
X
Capture triggered by negative edge on
CEXn
X
X
1
1
0
0
0
X
Capture triggered by transition on
CEXn
X
1
0
0
1
0
0
X
Software Timer
X
1
0
0
1
1
0
X
High Speed Output
X
1
0
0
X
1
1
X
Frequency Output
0
1
0
0
X
0
1
X
8-Bit Pulse Width Modulator
1
1
0
0
X
0
1
X
16-Bit Pulse Width Modulator
X = Don’t Care
Figure 23.3. PCA Interrupt Block Diagram
(for n = 0 to 4)
PCA0CPMn
P ECCMT P E
WCA A AOWC
MOPP TGMC
1 MPN n n n F
6nnn
n
n
PCA Counter/
Timer Overflow
PCA0CN
CC
FR
CCCCC
CCCCC
FFFFF
43210
PCA0MD
C
CCCE
I
PPPC
D
SSSF
L
210
0
1
PCA Module 0
(CCF0)
PCA Module 1
(CCF1)
PCA Module 2
(CCF2)
PCA Module 3
(CCF3)
PCA Module 4
(CCF4)
ECCF0
0
1
ECCF1
0
1
ECCF2
0
1
ECCF3
0
1
ECCF4
0
1
EPCA0
(EIE1.3)
EA
(IE.7)
0
1
0
Interrupt
Priority
1
Decoder
252
Rev. 1.4