C8051F800DK Silicon Laboratories Inc, C8051F800DK Datasheet - Page 135
![KIT DEV C8051F800](/photos/28/94/289400/mcudevkit_sml.jpg)
C8051F800DK
Manufacturer Part Number
C8051F800DK
Description
KIT DEV C8051F800
Manufacturer
Silicon Laboratories Inc
Type
MCUr
Specifications of C8051F800DK
Contents
Board, Cables, CD, Debugger, Power Supply
Processor To Be Evaluated
C8051F800
Data Bus Width
16 bit
Interface Type
USB
Operating Supply Voltage
7 V to 15 V
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
For Use With/related Products
C8051F8xx
Lead Free Status / Rohs Status
Supplier Unconfirmed
Other names
336-1797
- Current page: 135 of 250
- Download datasheet (2Mb)
C8051F80x-83x
22.3.1. External Crystal Example
If a crystal or ceramic resonator is used as an external oscillator source for the MCU, the circuit should be
configured as shown in Figure 22.1, Option 1. The External Oscillator Frequency Control value (XFCN)
should be chosen from the Crystal column of the table in SFR Definition 22.4 (OSCXCN register). For
example, an 11.0592 MHz crystal requires an XFCN setting of 111b and a 32.768 kHz Watch Crystal
requires an XFCN setting of 001b. After an external 32.768 kHz oscillator is stabilized, the XFCN setting
can be switched to 000 to save power. It is recommended to enable the missing clock detector before
switching the system clock to any external oscillator source.
When the crystal oscillator is first enabled, the oscillator amplitude detection circuit requires a settling time
to achieve proper bias. Introducing a delay of 1 ms between enabling the oscillator and checking the
XTLVLD bit will prevent a premature switch to the external oscillator as the system clock. Switching to the
external oscillator before the crystal oscillator has stabilized can result in unpredictable behavior. The rec-
ommended procedure is as follows:
1. Force XTAL1 and XTAL2 to a low state. This involves enabling the Crossbar and writing 0 to the port
pins associated with XTAL1 and XTAL2.
2. Configure XTAL1 and XTAL2 as analog inputs.
3. Enable the external oscillator.
4. Wait at least 1 ms.
5. Poll for XTLVLD = 1.
6. If desired, enable the Missing Clock Detector.
7. Switch the system clock to the external oscillator.
Important Note on External Crystals: Crystal oscillator circuits are quite sensitive to PCB layout. The
crystal should be placed as close as possible to the XTAL pins on the device. The traces should be as
short as possible and shielded with ground plane from any other traces which could introduce noise or
interference.
The capacitors shown in the external crystal configuration provide the load capacitance required by the
crystal for correct oscillation. These capacitors are "in series" as seen by the crystal and "in parallel" with
the stray capacitance of the XTAL1 and XTAL2 pins.
Note: The desired load capacitance depends upon the crystal and the manufacturer. Please refer to the crystal data
sheet when completing these calculations.
For example, a tuning-fork crystal of 32.768 kHz with a recommended load capacitance of 12.5 pF should
use the configuration shown in Figure 22.1, Option 1. The total value of the capacitors and the stray capac-
itance of the XTAL pins should equal 25 pF. With a stray capacitance of 3 pF per pin, the 22 pF capacitors
yield an equivalent capacitance of 12.5 pF across the crystal, as shown in Figure 22.2.
Rev. 1.0
135
Related parts for C8051F800DK
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![500SAAB8M00000ACF](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
SMD/C/SINGLE-ENDED OUTPUT SILICON OSCILLATOR
Manufacturer:
Silicon Laboratories Inc
![SI3210MFT](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![4010-DAAKF_868](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
N/A N/A/SI4010 AES KEYFOB DEMO WITH LCD RX
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![4010-DASKF_868](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
N/A N/A/SI4010 SIMPLIFIED KEY FOB DEMO WITH LED RX
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![4432-SEB1 C 915](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
N/A/-40 TO 85 OC/EZLINK MODULE; F930/4432 HIGH BAND (REV E/B1)
Manufacturer:
Silicon Laboratories Inc
![4432-SEB1 D 470](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
EZLink Module; F930/4432 Low Band (rev e/B1)
Manufacturer:
Silicon Laboratories Inc
![4460-TCE10D434-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4460 10 DBM RADIO TEST CARD 434 MHZ
Manufacturer:
Silicon Laboratories Inc
![4461-TSQ14D868-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4461 14 DBM RADIO TEST CARD 868 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TCE20C460-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4463 20 DBM RFSWITCH RADIO TEST CARD 460 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TCE20C868-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4463 20 DBM RADIO TEST CARD 868 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TCE27F868-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4463 27 DBM RADIO TEST CARD 868 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TCE30E915S-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4463 SKYWORKS 30 DBM RADIO TEST CARD 915 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TCE30E915R-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
N/A N/A/-40 TO 85 OC/4463 RFMD 30 DBM RADIO TEST CARD 915 MHZ
Manufacturer:
Silicon Laboratories Inc
![4463-TSQ20D169-EK](/images/manufacturer_photos/0/6/609/silicon_laboratories_inc_tmb.jpg)
Part Number:
Description:
I/4463 20 DBM RADIO TEST CARD 169 MHZ
Manufacturer:
Silicon Laboratories Inc