Manual

30
AT86RF401
1424D–RKE–09/02
Transmit Control Register – TX_CNTL
• Bit[7:6]
Reserved.
• Bit[5]: TXE, Transmitter Enable
This bit turns on the transmitter.
• Bit[4]: TXK, Transmitter Key
ThisbitisORedwiththeoutputfromthebittimer.Ifthebittimerisusedtokeythetrans-
mitter, the TXK bit should be programmed to “0”. If the bit timer is not used, this bit may
be used to manually key the transmitter.
Figure 25. Modulation Control Logic
• Bit[3]
Reserved.
• Bit[2]: LOC, PLL Lock
This bit is set when the frequency synthesizer in the transmitter is locked. Usually this bit
should be set before transmitting.
Power Attenuation Control Register – PWR_ATTEN
This register is used to select the power attenuation level. The total power attenuation is
the sum of the coarse attenuation and fine attenuation. As an example, to obtain 15 dB
of attenuation, the coarse setting of 12 dB and fine setting of 3 dB would be selected. To
obtain 12 dB coarse attenuation, Bits[5:3] would be set to [010]. To obtain 3 dB of fine
attentuation would require Bits[2:0] to be set to [011].
• Bits[7:6]
Reserved
Bit 76543210
$12 ––TXE TXK – LOC ––
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 00000000
Bit Timer
TXK
ON/OFF
POWER
AMP
PLL
RF
IN
RF
OUT
Bit 76543210
$14 ––PCC2 PCC1 PCC0 PCF2 PCF1 PCF0
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 00000000