RF31 Hope Microelectronics co., Ltd, RF31 Datasheet - Page 91

• Manufacturer Part Number: RF31
• Description: Rf31 Ism Receiver
• Manufacturer: Hope Microelectronics co., Ltd

Register 20h. Clock Recovery Oversampling Rate
Reset value = 01100100
The oversampling rate can be calculated as rxosr = 500 kHz/(2
dwn3_bypass values found at Address: 1Ch – IF Filter Bandwidth register together with the receive data rate (Rb)
are the parameters needed to calculate rxosr:
The Rb unit used in this equation is in kbps. The enmanch is the Manchester Coding parameter (see Reg. 70h,
enmach is 1 when Manchester coding is enabled, enmanch is 0 when disabled). The number found in the equation
should be rounded to an integer. The integer can be translated to a hexadecimal.
For optimal modem performance it is recommended to set the rxosr to at least 8. A higher rxosr can be obtained by
choosing a lower value for ndec_exp or enable dwn3_bypass. A correction in filset might be needed to correct the
channel select bandwidth to the desired value. Note that when ndec_exp or dwn3_bypass are changed the related
parameters (rxosr, ncoff and crgain) need to be updated.
Name
Type
7：0
Bit
Bit
Tel: [phone]
D7
rxosr[7:0]
Name
D6
Oversampling Rate.
3 LSBs are the fraction, default = 0110 0100 = 12.5 clock cycles per data bit
rxosr =
Fax: [phone]
D5
2
ndec_exp-3
500×(1+2×dwn3_bypass)
×Rb×（1+enmanch
D4
E-mail: [e-mail]
rxosr[7:0]
R/W
ndec_exp
Function
D3
x RX_DR). The ndec_exp and the
）
D2
http://www.hoperf.com
R F 3 1
D1
D0
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