C8051F340-GQR Silicon Laboratories Inc, C8051F340-GQR Datasheet - Page 261

• Manufacturer Part Number: C8051F340-GQR
• Description: MCU 8-Bit C8051F34x 8051 CISC 64KB Flash 3.3V/5V 48-Pin TQFP T/R
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051F340-GQR

• Package: 48TQFP
• Device Core: 8051
• Family Name: C8051F34x
• Maximum Speed: 48 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 40
• Interface Type: I2C/SMBus/SPI/UART/USB
• On-chip Adc: 17-chx10-bit
• Number Of Timers: 4
• Ram Size: 4.25 KB
• Program Memory Size: 64 KB
• Program Memory Type: Flash
• Operating Temperature: -40 to 85 °C

22.2.4. Frequency Output Mode
Frequency Output Mode produces a programmable-frequency square wave on the module’s associated
CEXn pin. The capture/compare module high byte holds the number of PCA clocks to count before the out-
put is toggled. The frequency of the square wave is then defined by Equation 22.1.
Where F
The lower byte of the capture/compare module is compared to the PCA counter low byte; on a match,
CEXn is toggled and the offset held in the high byte is added to the matched value in PCA0CPLn. Fre-
quency Output Mode is enabled by setting the ECOMn, TOGn, and PWMn bits in the PCA0CPMn register.
Note: A value of 0x00 in the PCA0CPHn register is equal to 256 for this equation.
PCA0CPLn
Write to
Reset
PCA
PCA0CPHn
Write to
is the frequency of the clock selected by the CPS2-0 bits in the PCA mode register, PCA0MD.
0
1
ENB
ENB
Equation 22.1. Square Wave Frequency Output
Figure 22.7. PCA Frequency Output Mode
W
M
P
1
6
n
x
O
M
E
C
n
PCA0CPMn
C
A
P
P
n
0 0 0
C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D
C
A
P
N
n
M
A
T
n
O
G
T
n
W
M
P
n
E
C
C
F
n
x
PCA Timebase
F
CEXn
Enable
=
Comparator
PCA0CPLn
Rev. 1.3
---------------------------------------- -
2
PCA0L

8-bit
PCA0CPHn
F
PCA
match
Enable
Adder
8-bit Adder
Toggle
TOGn
0
1
CEXn
PCA0CPHn
Crossbar
Port I/O
261