AN332 Datasheet, PDF (64/302 Pages) Silicon Laboratories – Si47XX PROGRAMMING GUIDE

AN332
5.2.1. FM/RDS Receiver Commands
Command 0x01. POWER_UP
Initiates the boot process to move the device from powerdown to powerup mode. The boot can occur from internal
device memory or a system controller downloaded patch. To confirm that the patch is compatible with the internal
device library revision, the library revision should be confirmed by issuing the POWER_UP command with
FUNC = 15 (query library ID). The device returns the response, including the library revision, and then moves into
powerdown mode. The device can then be placed in powerup mode by issuing the POWER_UP command with
FUNC = 0 (FM Receive) and the patch may be applied (See Section "7.2. Powerup from a Component Patch" on
page 216).
The POWER_UP command configures the state of ROUT (pin 13, Si474x pin 15) and LOUT (pin 14, Si474x pin
16) for analog audio mode and GPO2/INT (pin 18, Si474x pin 20) for interrupt operation. For the
Si4705/21/31/35/37/39/84/85-B20, the POWER_UP command also configures the state of GPO3/DCLK (pin 17,
Si474x pin 19), DFS (pin 16, Si474x pin 18), and DOUT (pin 15, Si474x pin 17) for digital audio mode. The
command configures GPO2/INT interrupts (GPO2OEN) and CTS interrupts (CTSIEN). If both are enabled,
GPO2/INT is driven high during normal operation and low for a minimum of 1 µs during the interrupt. The CTSIEN
bit is duplicated in the GPO_IEN property. The command is complete when the CTS bit (and optional interrupt) is
set.
Note: To change function (e.g. FM RX to AM RX or FM RX to FM TX), issue POWER_DOWN command to stop current func-
tion; then, issue POWER_UP to start new function.
Note: Delay at least 500 ms between powerup command and first tune command to wait for the oscillator to stabilize if
XOSCEN is set and crystal is used as the RCLK.
Available in: All
Command Arguments: Two
Response Bytes: None (FUNC = 0), Seven (FUNC = 15)
Command
Bit
D7
D6
D5
D4
D3
D2
D1
D0
CMD
0
0
0
0
0
0
0
1
ARG1
CTSIEN GPO2OEN PATCH XOSCEN
FUNC[3:0]
ARG2
OPMODE[7:0]
ARG Bit
1
7
1
6
1
5
Name
CTSIEN
GPO2OEN
PATCH
Function
CTS Interrupt Enable.
0 = CTS interrupt disabled.
1 = CTS interrupt enabled.
GPO2 Output Enable.
0 = GPO2 output disabled.
1 = GPO2 output enabled.
Patch Enable.
0 = Boot normally.
1 = Copy NVM to RAM, but do not boot. After CTS has been set, RAM may be
patched.
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Rev. 1.0