si4430 Silicon Laboratories, si4430 Datasheet - Page 144

• Manufacturer Part Number: si4430
• Description: Si4430 Ism Transceiver
• Manufacturer: Silicon Laboratories

Register 74h. Frequency Offset 2
Register 75h. Frequency Band Select
Si4430
Reset value = 00000000
Reset value = 01110101
The RF carrier frequency can be calculated as follows:
f
where parameters f
79h and 7Ah.
144
carrier
Name
Name
Type
Type
Bit
Bit
7:2
1:0
4:0
Bit
Bit
7
6
5
= (f
b
Reserved
+24+(f
Reserved
Reserved
Reserved
Name
fo[9:8]
Name
fb[4:0]
D7
D7
sbsel
R
c
+f
c
o
, f
) / 64000) x 10000 x 2+ (f
o
, f
Reserved.
Upper Bits of the Frequency Offset Setting.
fo[9] is the sign bit. The frequency offset can be calculated as Offset = 312.5 Hz x fo[7:0].
fo[9:0] is a twos complement value. Reading from this register will give the AFC correc-
tion last results, not this register value.
Reserved.
Side Band Select.
Reserved.
This bit must always be written to 1.
Frequency Band Select.
Every increment corresponds to a 20 MHz band.
fb=21 900–919.9 MHz
fb=22 920–939.9 MHz
fb=23 940–960 MHz
sbsel
b
R/W
D6
D6
and hb_sel come from registers 73h–77h. Parameters f
Reserved
R/W
D5
D5
Reserved
hch
R
Preliminary Rev. 0.4
x f
hs
D4
D4
x 10) [kHz],
Function
Function
D3
D3
fb[4:0]
R/W
D2
D2
hch
and f
hs
D1
D1
come from register
fo[9:8]
R/W
D0
D0