4313-T-B1_B_ANY Silicon Laboratories Inc, 4313-T-B1_B_ANY Datasheet - Page 33

• Manufacturer Part Number: 4313-T-B1_B_ANY
• Description: WiFi / 802.11 Modules & Development Tools WiFi/802.11 Modules & Development Tools
• Manufacturer: Silicon Laboratories Inc

Specifications of 4313-T-B1_B_ANY

• Wireless Frequency: 315 MHz to 915 MHz
• Modulation: FSK, OOK
• For Use With/related Products: Si4313
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.2. Microcontroller Clock
The Si4313 can divide its 30 MHz clock down internally, which can then be output to the microcontroller through
GPIO2. Additionally, a 32.768 kHz clock signal can also be derived from an internal RC Oscillator or an external
32 kHz Crystal. The GPIO2 default is the microcontroller clock with a 1 MHz microcontroller clock output.
This feature is useful to lower BOM cost by using only one crystal in the system. The system clock frequency is
selectable from one of eight options listed in Table 14.
Except for the 32.768 kHz option, all other frequencies are derived by dividing the Crystal Oscillator frequency. The
32.768 kHz clock signal is derived from an internal RC Oscillator or an external 32 kHz Crystal, depending on
which is selected. The GPIO2 default is the microcontroller clock with a 1 MHz microcontroller clock output.
If the microcontroller clock option is being used, there may be a need for a system clock for the microcontroller
while the Si4313 is in SLEEP mode. Since the crystal oscillator is disabled in SLEEP mode in order to save current,
the low-power 32.768 kHz clock can be automatically switched to become the microcontroller clock. This feature is
called enable low frequency clock and is enabled by the enlfc bit in Register 0Ah. Microcontroller Output Clock.
When enlfc = 1 and the chip is in SLEEP mode, the 32.768 kHz clock will be provided to the microcontroller as the
system clock, regardless of the setting of mclk[2:0]. For example, if mclk[2:0] = 000, 30 MHz will be provided
through the GPIO output pin to the microcontroller as the system Clock in all IDLE or RX states. When the chip
enters SLEEP mode, the system clock will automatically switch to 32.768 kHz from the RC oscillator or 32.768
crystal.
Add
0A
R/W
R/W Microcontroller Output Clock
Description
Func/
Table 14. System Clock Frequency Options
mclk[2:0]
000
001
010
100
101
011
110
111
D7 D6
Rev. 1.0
clkt[1]
D5
Clock Frequency
clkt[0]
32.768 kHz
D4
30 MHz
15 MHz
10 MHz
4 MHz
3 MHz
2 MHz
1 MHz
enlfc
D3
mclk[2] mclk[1] mclk[0]
D2
Si4313-B1
D1
D0
POR
06h
Def
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