Silicon Laboratories C8051F347 - Manual (Page 260)

C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D
260 Rev. 1.3
22.2.3. High Speed Output Mode
In High Speed Output mode, a module’s associated CEXn pin is toggled each time a match occurs
between the PCA Counter and the module's 16-bit capture/compare register (PCA0CPHn and
PCA0CPLn) Setting the TOGn, MATn, and ECOMn bits in the PCA0CPMn register enables the
High-Speed Output mode.
Important Note About Capture/Compare Registers : When writing a 16-bit value to the PCA0 Capture/
Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit
to ‘0’; writing to PCA0CPHn sets ECOMn to ‘1’.
Figure 22.6. PCA High Speed Output Mode Diagram
Match
16-bit Comparator
PCA0H
PCA0CPHn
Enable
PCA0L
PCA
Timebase
PCA0CPLn
0
1
0 0 0 x
ENB
ENB
0
1
Write to
PCA0CPLn
Write to
PCA0CPHn
Reset
PCA0CPMn
P
W
M
1
6
n
E
C
O
M
n
E
C
C
F
n
T
O
G
n
P
W
M
n
C
A
P
P
n
C
A
P
N
n
M
A
T
n
x
CEXn
Crossbar Port I/O
Toggle
0
1
TOGn
PCA0CN
C
F
C
R C
C
F
0
C
C
F
2
C
C
F
1
C
C
F
4
C
C
F
3
PCA Interrupt