ATMEGA128RFA1_11 ATMEL [ATMEL Corporation], ATMEGA128RFA1_11 Datasheet - Page 114

• Manufacturer Part Number: ATMEGA128RFA1_11
• Description: 8-bit Microcontroller with Low Power 2.4GHz Transceiver for ZigBee and IEEE 802.15.4
• Manufacturer: ATMEL [ATMEL Corporation]

9.12.17 ANT_DIV – Antenna Diversity Control Register
114
ATmega128RFA1
Table 9-46 OQPSK_DATA_RATE Register Bits
This register controls the Antenna Diversity.
• Bit 7 – ANT_SEL - Antenna Diversity Antenna Status
This register bit signals the currently selected antenna path. The selection may be
based either on the last antenna diversity cycle (ANT_DIV_EN = 1) or on the content of
register bits ANT_CTRL.
Table 9-47 ANT_SEL Register Bits
• Bit 6:4 – Res2:0 - Reserved
• Bit 3 – ANT_DIV_EN - Enable Antenna Diversity
If this register bit is set the Antenna Diversity algorithm is enabled. On reception of a
frame the algorithm selects an antenna autonomously during SHR search. This
selection is kept until
1. a new SHR search starts or
2. receive states are left or
3. a manually programming of bits ANT_CTRL occurred. If ANT_DIV_EN = 1 the bit
ANT_EXT_SW_EN shall also be set to 1.
Table 9-48 ANT_DIV_EN Register Bits
• Bit 2 – ANT_EXT_SW_EN - Enable External Antenna Switch Control
If enabled, pin DIG1 and pin DIG2 become output pins and provide a differential control
signal for an external Antenna Diversity switch. The selection of a specific antenna is
done either by the automatic Antenna Diversity algorithm (ANT_DIV_EN = 1) or
Bit
NA ($14D)
Read/Write
Initial Value
Bit
NA ($14D)
Read/Write
Initial Value
Register Bits
OQPSK_DATA_RATE1:0
Register Bits
ANT_SEL
Register Bits
ANT_DIV_EN
ANT_DIV_EN
ANT_SEL
RW
R
7
0
3
0
ANT_EXT_SW_EN
Res2
RW
R
6
0
2
0
Value
Value
Value
0
1
2
3
0
1
0
1
ANT_CTRL1
Res1
Description
250 kb/s (IEEE 802.15.4 compliant)
500 kb/s
1000 kb/s
2000 kb/s
Description
Antenna 0
Antenna 1
Description
Antenna Diversity algorithm disabled
Antenna Diversity algorithm enabled
R
5
0
RW
1
1
ANT_CTRL0
Res0
R
4
0
RW
0
1
8266C-MCU Wireless-08/11
ANT_DIV
ANT_DIV