C8051F336/7/8/9
25.2. PCA0 Interrupt Sources
Figure 25.3 shows a diagram of the PCA interrupt tree. There are five independent event flags that can be
used to generate a PCA0 interrupt. They are: the main PCA counter overflow flag (CF), which is set upon
a 16-bit overflow of the PCA0 counter, an intermediate overflow flag (COVF), which can be set on an over-
flow from the 8th, 9th, 10th, or 11th bit of the PCA0 counter, and the individual flags for each PCA channel
(CCF0, CCF1, and CCF2), which are set according to the operation mode of that module. These event
flags are always set when the trigger condition occurs. Each of these flags can be individually selected to
generate a PCA0 interrupt, using the corresponding interrupt enable flag (ECF for CF, ECOV for COVF,
and ECCFn for each CCFn). PCA0 interrupts must be globally enabled before any individual interrupt
sources are recognized by the processor. PCA0 interrupts are globally enabled by setting the EA bit and
the EPCA0 bit to logic 1.
(for n = 0 to 2)
PCA0CPMn
PCA0CN
PCA0MD
PCA0PWM
P E C C M T P E
W C A A A O W C
M O P P T G M C
1 M P N n n n F
C C
F R
C C C
C C C
F F F
2 1 0
C WW C C C E
I D D P P P C
D T L S S S F
L E C 2 1 0
K
A C E
C C
L L
S S
E E
L L
1 0
R O C
S V O
E F V
L
6 n n n
n
n
PCA Counter/Timer 8, 9,
10 or 11-bit Overflow
Set 8, 9, 10, or 11 bit Operation
EPCA0
0
1
PCA Counter/Timer 16-
bit Overflow
0
1
EA
ECCF0
Interrupt
Priority
Decoder
0
1
0
1
0
1
PCA Module 0
(CCF0)
ECCF1
ECCF2
0
1
PCA Module 1
(CCF1)
0
1
PCA Module 2
(CCF2)
Figure 25.3. PCA Interrupt Block Diagram
Rev. 0.2
211
SILICON [ SILICON ]
