MICRF505DEV1 Micrel Inc, MICRF505DEV1 Datasheet - Page 23

• Manufacturer Part Number: MICRF505DEV1
• Description: KIT DEV RADIOWIRE 850-950MHZ
• Manufacturer: Micrel Inc
• Series: RadioWire®r
• Type: Transceiver, ISMr

Specifications of MICRF505DEV1

• Frequency: 850MHz ~ 950MHz
• For Use With/related Products: MICRF505
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-1606

Bit Synchronizer
A bit synchronizer can be enabled in receive mode
by selecting the synchronous mode (Sync_en=1).
The DataClk pin will output a clock with twice the
frequency of the bit rate (a bit rate of 20 kbit/sec
gives a DataClk of 20 kHz). A received symbol/bit on
DataIXO will be output on rising edge of DataClk.
The micro controller should therefore sample the
symbol/bit on falling edge of DataClk.
The bit synchronizer uses a clock which needs to be
programmed according to the bit rate. The clock
frequency should be 16 times the actual bit rate (a
bit rate of 20 kbit/sec needs a bit synchronizer clock
with frequency of 320 kHz). The clock frequency is
set by the following formula:
f
0000110
0000111
BITSYNC
October 2006
A6..A0
_
BitRate_clkS1
CLK
D7
-
=
Re
fclk
BitRate_clkS0
ModclkS2
_
K
D6
×
2
f
XCO
7 (
−
BITSYNC
RefClk_K5
ModclkS1
D5
_
clkS
)
RefClk_K4
ModclkS0
D4
23
BitSync_clkS2
RefClk_K3
where
Refclk_K is also used to derive the modulator clock
and the bit rate clock.
At the beginning of a received data package, the bit
synchronizer clock frequency is not synchronized to
the bit rate. When these two are maximum offset to
each
synchronization is achieved.
D3
f
frequency (16 times higher than the bit rate)
f
Refclk_K: 6 bit divider, values between 1 and
63
BitSync_clkS: Bit synchronizer setting, values
between 0 and 7
BITSYNC_CLK
XCO
other,
: Crystal oscillator frequency
BitSync_clkS1
RefClk_K2
it
D2
:
takes
The
bit
BitSync_clkS0
22
RefClk_K1
D1
synchronizer
bit/symbols
[phone]
M9999-103106
BitRate_clkS2
RefClk_K0
D0
before
clock