NXP Semiconductors
FXPS7115D4
Digital absolute pressure sensor, 40 kPa to 115 kPa
7.5.3 Command summary
7.5.3.1 Register read command
The device supports a register read command. The register read command uses the
upper 7 bits of the addresses defined in Section 7.6 "User-accessible data array" to
address 8-bit registers in the register map.
The response to a register read command is shown in Section 7.5.3.1.2 "Register read
response message format". The response is transmitted on the next SPI message if and
only if all of the following conditions are met:
• No SPI error is detected (see Section 7.5.5.3 "SPI error" )
• No MISO error is detected (see Section 7.5.5.4 "SPI data output verification error")
If these conditions are met, the device responds to the register read request as shown
in Section 7.5.3.1.2 "Register read response message format". Otherwise, the device
responds with the error response as defined in Section 7.5.5.2 "Error responses". The
register read response includes the register contents at the rising edge of SS_B for the
register read command.
7.5.3.1.1 Register read command message format
Table 12.ꢀRegister read command message format
MSB: bit 31; LSB: bit 0
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17
Register access command
Register address
16
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Command
C[3:0]
Fixed bits:
must = 0h
Register data
8-bit CRC
1
1
0
0
0
0
0
0
RA[7:1]
RA[0]
0
0
0
0
0
0
0
0
CRC[7:0]
Table 13.ꢀRegister read command message bit field descriptions
Bit field
Definition
C[3:0]
Register read command = '1100'
RA[7:0]
CRC[7:0]
RA[7:1] contains the word address of the register to be read.
Read CRC Section
7.5.3.1.2 Register read response message format
Table 14.ꢀRegister read response message format
MSB: bit 31; LSB: bit 0
31 30 29 28 27
26
25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Register access command
Command
C[0], [3:1]
Basic
Status
Unused
Data 0h
Register data: contents
of RA[7:1] high byte
Register data: contents
of RA[7:1] low byte
8-bit CRC
0
1
1
0
ST[1:0]
0
0
RD[15:8]
RD[7:0]
CRC[7:0]
FXPS7115D4
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© NXP B.V. 2019. All rights reserved.
Product data sheet
Rev. 3 — 5 December 2019
21 / 72
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