Silicon Laboratories Si4704 Series Programming Manual page 76

AN332
Command 0x81. GPIO_SET
Sets the output level (high or low) for GPO1, 2, and 3. GPO1, 2, and 3 can be configured for output by setting the
GPO1OEN, GPO2OEN, and GPO3OEN bit in the GPIO_CTL command. To avoid excessive current consumption
due to oscillation, GPO pins should not be left in a high impedance state. The CTS bit (and optional interrupt) is set
when it is safe to send the next command. This property may only be set or read when in powerup mode. The
default is all GPO pins set for high impedance.
Note: GPIO_SET is fully-supported in FMRX comp 2.0 or higher. Only bit GPO3LEVEL is supported in FMRX comp 1.0.
Command arguments: One
Response bytes: None
Command
Bit D7
CMD 1
ARG1 0
ARG Bit
1 7:4
1 3 GPO3LEVEL
1 2 GPO2LEVEL
1 1 GPO1LEVEL
1 0
Response
Bit D7
CTS
STATUS
76
D6 D5 D4
0 0 0
0 0 0
Name
Reserved Always write 0.
GPO3 Output Level.
0 = Output low (default).
1 = Output high.
GPO3 Output Level.
0 = Output low (default).
1 = Output high.
GPO3 Output Level.
0 = Output low (default).
1 = Output high.
Reserved Always write 0.
D6 D5
ERR X
Confidential Rev. 0.2
D3 D2
0 0
GPO3LEVEL GPO2LEVEL
Function
D4 D3
X X RDSINT
D1
0
GPO1LEVEL
D2 D1
ASQINT STCINT
D0
1
0
D0