AK2401 Datasheet, PDF (89/103 Pages) Asahi Kasei Microsystems – Direct Conversion Transceiver

[AK2401]
RSSIAVE[2:0]: RSSI Averaging Setting
The signal from RSSI circuit is averaged by output sampling rate. Set the number of averaging
operation by RSSIAVE bits. The setting of the output sampling rate is DFIL_SR[1:0] bits = “00”
<Address0x22>.
RSSIAVE
[2] [1] [0]
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Averaging [Times]
4 (default)
8
16
32
64
128
15.22. <0x2D>FIR COEF
Address
D7
D6
D5
D4
D3
D2
D1
D0
R/W
0x2D
COEF_NUM[6:0]
COEF_ST
R/W
Initial value
0
0
0
0
0
0
0
0
Refer to “13.8.3. Programmable FIR” for setting details.
COEF_NUM[6:0]: TAP Number Setting for Programmable FIR Filter
Set the TAP number of programmable FIR filter. This setting must be in the range shown below. If the
setting of COEF_NUM bits is more than 75, it will be recognized as 75 as the limit of the setting.
<Address0x22> DFIL_SEL[3:0] bits = 0~3(dec): 1 ≤ COEF_NUM ≤ 64
<Address0x22> DFIL_SEL[3:0] bits = 4~15(dec): 1 ≤ COEF_NUM ≤ 75
The AK2401 cannot be in FIR filter coefficient write mode even if COEF_ST bit is set to “1” when
COEF_NUM[6:0] bits are set to “0000000”. Therefore, it is recommended to set COEF_NUM[6:0] bits
“0000000” after writing coefficient to prevent unintended change of the setting.
COEF_ST: Start Trigger of Coefficient Write Mode
When setting this bit to “1”, the serial interface for register writing enters FIR filter coefficient write mode.
Write coefficient continuously for the number of times of the TAP number set by COEF_NUM[6:0] bits.
COEF_ST bit returns to “0” automatically after finish writing the coefficient and normal register write
becomes available.
017003093-E-00
89
2017/3