Silicon Laboratories Si475X Series, Programming Manual

Page: 5 / 285

AN543
Rev. 0.9 5
Example (with crystal 4 MHz, FM function):
1. Provide the initial POWER_UP Command:
2. Apply a wait time of at least 100 ms.
3. Apply the following command:
4. Apply the following command:
Note:
For more details on the external circuit for the 4 MHz crystal, see “AN750: Si475x 4 MHz Crystal Circuit and Power-Up
Procedure”.
5. The device is ready to commence normal operation and accept additional commands. Refer to Figure 3.
Action Data Description
CMD 0x01 POWER_UP
ARG1 0X77 NORMAL OPERATION, 4 MHz Crystal
ARG2 0x1F SETS CRYSTAL LOAD CAPACITANCE
Note:
Change this value to the capacitance that matches the crystal in use.
ARG3 0x27 SETS CRYSTAL BIAS = 7 w/ FASTBOOT
ARG4 0x00
0x10
0x20 BOOT LOADER
FM Receive, 4 MHz Crystal
AM Receive, 4 MHz Crystal
ARG5 0x00 DIGITAL CORE DISABLED/CRYSTAL OSCILLATOR DISABLED
STATUS NO CTS bit returned
Action Data Description
CMD 0xFB CONTROL REGISTER WRITE COMMAND
ARG1 0X06 CONTROL REGISTER ADDRESS
ARG2 0x80 FORCES CTS = 1
STATUS NO CTS bit returned
Action Data Description
CMD 0x01 POWER_UP
ARG1 0X77 NORMAL OPERATION, 4 MHz Crystal
ARG2 0x1F SETS CRYSTAL LOAD CAPACITANCE
Note:
Change this value to the capacitance that matches the crystal in use.
ARG3 0x23 SETS CRYSTAL BIAS = 3 w/ FASTBOOT
ARG4 0x00
0x10
0x20 BOOT LOADER
FM Receive, 4 MHz Crystal
AM Receive, 4 MHz Crystal
ARG5 0x11 DIGITAL CORE ENABLED/CRYSTAL OSCILLATOR ENABLED
STATUS CTS = 1