C8051F300DK Silicon Laboratories Inc, C8051F300DK Datasheet - Page 158

• Manufacturer Part Number: C8051F300DK
• Description: DEV KIT F300/301/302/303/304/305
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F300DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F30x
• Interface Type: USB
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F300
• Silicon Family Name: C8051F30x
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Silicon Laboratories C8051 F300/001/002
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1246

C8051F300/1/2/3/4/5
16.2.1. Edge-triggered Capture Mode
In this mode, a valid transition on the CEXn pin causes the PCA to capture the value of the PCA counter/
timer and copy it into the corresponding module's 16-bit capture/compare register (PCA0CPLn and
PCA0CPHn). The CAPPn and CAPNn bits in the PCA0CPMn register are used to select the type of transi-
tion that triggers the capture: low-to-high transition (positive edge), high-to-low transition (negative edge),
or either transition (positive or negative edge). When a capture occurs, the Capture/Compare Flag (CCFn)
in PCA0CN is set to logic 1 and an interrupt request is generated if CCF interrupts are enabled. The CCFn
bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and
must be cleared by software. If both CAPPn and CAPNn bits are set to logic 1, then the state of the Port
pin associated with CEXn can be read directly to determine whether a rising-edge or falling-edge caused
the capture.
Note: The CEXn input signal must remain high or low for at least 2 system clock cycles to be recognized by the
158
Port I/O
hardware.
Crossbar
Figure 16.4. PCA Capture Mode Diagram
CEXn
W
P
M
1
6
n
x
PCA0CPMn
O
M
E
C
n
0
Rev. 2.9
C
A
P
P
n
C
A
P
N
n
0
1
M
A
T
n
0 0 0 x
T
O
G
n
W
M
P
n
E
C
C
F
n
0
1
C
F
C
R
PCA0CN
PCA
Timebase
C
C
F
2
C
C
F
1
C
C
F
0
PCA Interrupt
Capture
PCA0CPLn
PCA0L
PCA0CPHn
PCA0H