SCA8X0/21X0/3100 Series
Table 3: SCA21X0 and SCA31X0 start up sequence
Item
1
Procedure
Set Vdd=3.0...3.6V
Functions
Check
-
•
•
•
•
Release part from
reset
2
Wait 35ms
-
Memory reading
and self-diagnostic
Settling of signal
path
Acknowledge for
possible saturation
(SAT-bit)
3
Read INT_STATUS
•
•
SPI fixed bits
SPI ST=0
•
Checksum pass
detected from SPI
frame
4
Write
CTRL=00001010 (a)
or
CTRL=00001000 (b)
or
CTRL=00000000 (c)
Wait 10ms
Read CTRL
•
•
•
•
SPI fixed bits
SPI FRME=0
SPI ST=0
•
•
•
Set PORST=0 (abc)
Start STC (ab)
Start STS (a)
SPI SAT=0
5
6
STS calculation
-
•
Check that STC is
on, if enabled
Check that STS is
over if enabled
•
•
•
•
•
•
•
•
•
•
•
•
•
•
CTRL.ST=1
CTRL.ST_CFG=0
SPI fixed bits
SPI FRME=0
SPI PORST=0
SPI ST=0
•
SPI SAT=0
dPAR, data parity
SPI fixed bits
SPI FRME=0
SPI PORST=0
SPI ST=0
7
Read Z_MSB, Z_LSB, Read acceleration data
Y_MSB, Y_LSB,
X_MSB, X_LSB
SPI SAT=0
dPAR, data parity
2.6 Recommended operation sequence
Table 4: Reading of the acceleration data
Item
1
Procedure
Read acceleration data
Functions
Desired x, y,
or/and z-data
Check
•
•
•
•
•
•
SPI fixed bits
SPI FRME=0
SPI PORST=0
SPI ST=0
SPI SAT=0
dPAR, data
parity
2
3
4
Repeat item 1 (N-1) times
Noise
averaging
Noise
averaging
Desired x, y,
or/and z-data
(one read
before sending
-
-
Calculate average (AVE) of
N-samples
Read acceleration data
•
•
•
SPI fixed bits
SPI FRME=0
SPI PORST=0
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