C8051F537-IT Silicon Laboratories Inc, C8051F537-IT Datasheet - Page 200

• Manufacturer Part Number: C8051F537-IT
• Description: IC 8051 MCU 2K FLASH 20TSSOP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F53xr

Specifications of C8051F537-IT

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 16
• Program Memory Size: 2KB (2K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.25 V
• Data Converters: A/D 16x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 20-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: 336-1401

C8051F52x/F52xA/F53x/F53xA
19.2.4. 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 19.1.
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.
200
Note: A value of 0x00 in the PCA0CPHn register is equal to 256 for this equation.
W
M
P
1
6
n
0
PCA0CPMn
O
M
E
C
n
C
A
P
P
n
0 0 0
C
A
P
N
n
PCA
M
A
T
n
O
G
T
n
1
W
M
P
n
is the frequency of the clock selected by the CPS2-0 bits in the PCA mode register, PCA0MD.
E
C
C
F
n
0
PCA Timebase
Enable
Equation 19.1. Square Wave Frequency Output
Figure 19.7. PCA Frequency Output Mode
Comparator
PCA0CPLn
PCA0L
8-bit
F
CEXn
=
Rev. 1.3
---------------------------------------- -
2
match

Enable
Adder
PCA0CPHn
8-bit Adder
F
Toggle
PCA
TOGn
0
1
CEXn
PCA0CPHn
Crossbar
Port I/O