Texas Instruments CC2500 - Page 68

CC2500
S
WRS040
C
Page
68
of
89
0x13: MDMCFG1
–
Modem
C
onfiguration
Bit
Field Name
Reset
R/W
Description
7
FEC_EN
0
R/W
Enable Forward Error Correction (FEC) with interleaving for
packet payload
0 = Disable
1 = Enable
(Only supported for fix
ed packet length mode, i.e.
PKTCTRL0.LENGTH_CONFIG
=0
)
6:4
NUM_PREAMBLE[2:0]
2 (010)
R/W
Sets the minimum number of preamble bytes to be transmitted
Setting
Number of preamble bytes
0 (000)
2
1 (001)
3
2 (010)
4
3 (011)
6
4 (100)
8
5 (101)
12
6 (110)
16
7 (111)
24
3:2
Reserved
R0
1:0
CHANSPC_E[1:0]
2 (10)
R/W
2 bit exponent of channel spacing
0x14: MDMCFG0
–
Modem
C
onfiguration
Bit
Field Name
Reset
R/W
Description
7:0
CHANSPC_M[7:0]
248 (0xF8)
R/W
8
-
bit mantiss
a of channel spacing. The channel spacing is
multiplied by the channel number CHAN and added to the base
frequency. It is unsigned and has the format:


E
CHANSPC
XOSC
CHANNEL
M
CHANSPC
f
f
_
18
2
_
256
2





The default values give 199.951 kHz channel spacing (the closest
setting to 200 kHz
), assuming 26.0 MHz crystal frequency.