Data Sheet
Bosch Sensortec | BME280 Data sheet
35 | 55
Modifications reserved | Data subject to change without notice
Document number: BST-BME280-DS002-15
Revision_1.6_092018
6.3.2 SPI read
Reading is done by lowering CSB and first sending one control byte. The control bytes consist of the
SPI register address (= full register address without bit 7) and the read command (bit 7 = RW = ‘1’).
After writing the control byte, data is sent out of the SDO pin (SDI in 3-wire mode); the register address
is automatically incremented. The SPI read protocol is depicted in Figure 13.
Start
RW Stop
1 1 1 1 0 1 1 0 bit15 bit14 bit13 bit12 bit11 bit10 bit9 bit8 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
CSB
=
1
Data byte
Data register - address F7h
Register address (F6h)
CSB
=
0
Control byte
Data byte
Data register - address F6h
Figure 13: SPI multiple byte read
6.4 Interface parameter specification
6.4.1 General interface parameters
The general interface parameters are given in Table 32 below.
Table 32: interface parameters
Parameter
Symbol
Condition
Min
Typ
Max
Unit
Input low level
V
il_si
V
DDIO
=1.2 V to 3. 6V
20
%V
DDI
O
Input high level
V
ih_si
V
DDIO
=1.2 V to 3.6 V
80
%V
DDI
O
Output low level I
2
C
V
ol_SDI
V
DDIO
=1.62 V, I
ol
=3 mA
20
%V
DDI
O
Output low level I
2
C
V
ol_SDI_1.2
V
DDIO
=1.20 V, I
ol
=3 mA
23
%V
DDI
O
Output low level SPI
V
ol_SDO
V
DDIO
=1.62 V, I
ol
=1 mA
20
%V
DDI
O
Output low level SPI
V
ol_SDO_1.2
V
DDIO
=1.20 V, I
ol
=1 mA
23
%V
DDI
O
Output high level
V
oh
V
DDIO
=1.62 V, I
oh
=1 mA
(SDO, SDI)
80
%V
DDI
O
Output high level
V
oh_1.2
V
DDIO
=1.20 V, I
oh
=1 mA
(SDO, SDI)
60
%V
DDI
O
Pull-up resistor
R
pull
Internal CSB pull-up
resistance to V
DDIO
70
120
190
kΩ
I
2
C bus load capacitor
C
b
On SDI and SCK
400
pF
6.4.2 I²C timings
For I²C timings, the following abbreviations are used:
“S&F mode” = standard and fast mode
“HS mode” = high speed mode
C
b
= bus capacitance on SDA line
All other naming refers to I²C specification 2.1 (January 2000).
The I²C timing diagram is in Figure 14. The corresponding values are given in Table 33.