NXP Semiconductors
FXTH87E
FXTH87E, Family of Tire Pressure Monitor Sensors
divided into two pages of 128 bits as selected by the RPAGE bit in the RFCR2. These as
described in Table 159. These bits are unaffected by any reset.
The data buffer is unloaded to the RF output starting with the least significant bit (RFD0)
in the least significant byte (RFB0) up through the most significant bit (RFD255) in the
most significant byte (RFB31). This is often referred to as "little-endian" data ordering.
The output of this data by the RFM in all 256 bits locations is not dependent on the state
of the RPAGE bit.
Table 159.ꢀRF data registers (RFD[31:0])
Bit 7
6
5
4
3
2
1
Bit 0
$003C
$003D
$003E
$003F
$0040
$0041
$0042
$0043
$0044
$0045
$0046
$0047
$0048
$0049
$004A
$004B
RFD[7:0] for RPAGE = 0, RFD[135:128] for RPAGE = 1
RFD[15:8] for RPAGE = 0, RFD[143:136] for RPAGE = 1
RFD[23:16] for RPAGE = 0, RFD[151:144] for RPAGE = 1
RFD[31:24] for RPAGE = 0, RFD[159:152] for RPAGE = 1
RFD[39:32] for RPAGE = 0, RFD[167:160] for RPAGE = 1
RFD[47:40] for RPAGE = 0, RFD[175:168] for RPAGE = 1
RFD[55:48] for RPAGE = 0, RFD[183:176] for RPAGE = 1
RFD[63:56] for RPAGE = 0, RFD[191:184] for RPAGE = 1
RFD[71:64] for RPAGE = 0, RFD[199:192] for RPAGE = 1
RFD[79:72] for RPAGE = 0, RFD[207:200] for RPAGE = 1
RFD[87:80] for RPAGE = 0, RFD[215:208] for RPAGE = 1
RFD[95:88] for RPAGE = 0, RFD[223:216] for RPAGE = 1
RFD[103:96] for RPAGE = 0, RFD[231:224] for RPAGE = 1
RFD[111:104] for RPAGE = 0, RFD[239:232] for RPAGE = 1
RFD[119:112] for RPAGE = 0, RFD[247:240] for RPAGE = 1
RFD[127:120] for RPAGE = 0, RFD[255:248] for RPAGE = 1
Table 160.ꢀRFD[31:0] field descriptions
Field
Description
RFD[127:0]
RF Data Registers Lower 128 bits — These are read/write bits that hold the lower 128 bits of possible
data to be sent by the RFM. Access to the lower 128 bits occurs when the RPAGE bit is clear. These
bits are unaffected by any reset.
(RFD[15:0],
RPAGE = 0)
RFD[255:128]
RF Data Registers Upper 128 bits — These are read/write bits that hold the upper 128 bits of
possible data to be sent by the RFM. Access to the lower 128 bits occurs when the RPAGE bit is
clear. These bits are unaffected by any reset.
(RFD[31:16]
, RPAGE = 1)
15.21 VCO calibration machine
The RFM incorporates a VCO calibration machine which works in conjunction with the
VCO. The calibration machine selects the optimal VCO sub-band with respect to a
predefined reference voltage applied to the VCO.
• Calibration supports maxband VCO sub-bands. Maxband corresponds to the band
where the VCO frequency is maximum.
FXTH87ERM
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