FXTH870xD
Sensors
106
Freescale Semiconductor, Inc.
12.17.6 LFR Data Register (LFDATA, LPAGE = 0)
The LFDATA is a read-only register that contains the most recent received data value. It is only accessible when the LPAGE bit
is clear. As data is serially received by the LFR, it is assembled into 8-bit values. When a new complete 8-bit value is received,
it is moved into the LFDATA register, over-writing any previous value, and the LFDRF data ready flag is set to indicate a value is
available for the MCU to read. If a previous value was ready but was not read out of the LFDATA register before a new data byte
is ready, the LFOVF overflow flag is also set to indicate this overflow condition. Writes to LFDATA have no meaning or effect.
12.17.7 LFR ID Registers (LFIDH:LFIDL, LPAGE = 0)
These two 8-bit read/write registers hold one of two ID values for LF messages. They are only accessible when the LPAGE bit
is clear. The type of ID checking can be selected or disabled by using the IDSEL[1:0] bits in the LFCTL1 register. When ID
checking is enabled, the ID value received through the LFR must match the contents of the LFIDH and/or LFIDL registers
depending on the IDSEL bits or the message will be ignored and the MCU will remain in standby mode to minimize power
consumption. All these bits are cleared by a reset.
$0025
Bit 7
6
5
4
3
2
1
Bit 0
R
RXDATA[7:0]
W
Reset:
0
0
0
0
0
0
0
0
= Reserved
Figure 81. LFR Data Register (LFDATA) when LPAGE = 0
Table 64. LFDATA Register Field Descriptions
Field
Description
7:0
RXDATA
[7:0]
Receive Data [7:0]
— This is the received data from the LFR when in the data mode. All bits are read-only and any writes to
these bits will be ignored. Reading this register will clear the LFDRF.
$0026
Bit 7
6
5
4
3
2
1
Bit 0
R
ID[0:7]
W
Reset:
0
0
0
0
0
0
0
0
Figure 82. LFR ID Low Byte (LFIDL)
$0027
Bit 7
6
5
4
3
2
1
Bit 0
R
ID[15:8]
W
Reset:
0
0
0
0
0
0
0
0
Figure 83. LFR ID High Byte (LFIDH)
Table 65. LFR ID Register Field Description
Field
Description
ID[15:0]
ID bits 15 through 0
— These read/write bits contain bits 15 through 0 of the 16-bit ID value.
Summary of Contents for FXTH870 D Series
Page 86: ...FXTH870xD Sensors 84 Freescale Semiconductor Inc Figure 57 Data Flow For Measurements...
Page 171: ...FXTH870xD Sensors Freescale Semiconductor Inc 169 Figure 128 QFN Case Outline...
Page 172: ...FXTH870xD Sensors 170 Freescale Semiconductor Inc Figure 129 QFN Case Outline...
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