7.8.3 Read Command. AMS AS8510
Reklamë
Reklamë
CS
SCLK
SDI
SDO
AS8510
Datasheet - D e t a i l e d D e s c r i p t i o n
7.8.3 Read Command
For Read command C0=1. After the command code C0, the address of register to be read is provided from MSB to LSB. Then one or more data bytes can be transferred from the SPI slave to the master, always from MSB to LSB. To transfer more bytes from consecutive addresses, SPI master keeps CS signal LOW and SPI clock active as long as it desires to read data from the slave. Each bit of the command and address of the frame is to be driven by the SPI master on the SPI clock transfer edge where SPI slave samples it on the next SPI clock edge.
Each bit of the data section of the frame is driven by the SPI slave on the SPI clock transfer edge and SPI master samples it on the next SPI
clock edge. These edges are determined as per Table 29
and examples of read command without and with address self-increment.
Figure 13. Protocol for Serial Data Read with Length = 1
1
A6
A5 A4 A3 A2 A1 A0
D7 D6 D5
Data D7 – D0 at
Address A4..A0 is read here
D4 D3 D2 D1 D0
Figure 14. Protocol for Serial Data Read with Length = 4
CS
SCLK
SDI
1
A
6
A
5
A
4
A
3
A
2
A
1
A
0
SDO
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
Data D7-D0 at
Address A4-A0 is read here
Data D7-D0 at
Address A4-A0 +1 is read here
Data D7-D0 at
Address A4-A0 +2 is read here
Data D7-D0 at
Address A4-A0 +3 is read here
Data D7-D0 at
Address A4-A0 +4 is read here www.ams.com/AS8510 Revision 3.8
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Shkarko
Reklamë