AS3910-BQFP 查看數據表（PDF） - austriamicrosystems AG
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AS3910-BQFP Datasheet PDF : 47 Pages
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AS3910
Data Sheet - Application Information
Figure 6. Writing of Register Data with Auto-Incrementing Address
SEN
SCLK
SDATAI
X 0 0 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6
D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
Two leading
Zeros indicate
WRITE Mode
Data is moved to
Address
<A5-A0>
Data is moved to
Address
<A5-A0> + 1
Data is moved to
Address
<A5-A0> + (n-1)
Data is moved to
Address
<A5-A0> + n
X
SEN fall-
ing edge
signals
end of
WRITE
Mode
8.9.4 Reading of Data from Addressable Registers (READ Mode)
The command control Byte for a read command consists of a command code and an address. After the command code, the address of register
to be read has to be provided from the MSB to the LSB. Then one or more data bytes can be transferred from the SPI slave to the master, always
from the MSB to the LSB. As in case of the write command also the read command supports auto-incrementing address. To transfer bytes from
consecutive addresses, SPI master has to keep the SEN signal high and the SCLK has to be active as long as data need to be read from the
slave.
SDATAI is sampled at the falling edge of SCLK (like shown in the following diagrams), data to be read from the AS3910 internal register is driven
to SDATAO pin on rising edge of SCLK and is sampled by the master (μC) at the falling edge of SCLK.
A SEN LOW pulse has to be performed after register data has been transferred in order to indicate the end of the READ command and prepare
the Interface to the next command control Byte.
In case the register on defined address does not exist all 0 data is sent to SDATAO. Figure 7 illustrates an example for reading of a single byte.
Figure 7. Reading of a Single Register Byte
SEN
SCLK
SDATAI
0 1 A5 A4 A3 A2 A1 A0
X
SDATAO
01 pattern indi-
cates READ
Mode
X
D7 D6 D5 D4 D3 D2 D1 D0
X
SCLK raising
edge data is
transferred from
µC
SCLK
falling edge
Data is sampled
SCLK
raising edge
Data is moved
from Address
<A5-A0>
SCLK
falling edge
Data is
transferred
to µC
SEN falling
edge signals
end of READ
Mode
www.austriamicrosystems.com/HF_RFID_Reader/AS3910
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