MA800 – 8-BIT, DIGITAL ANGLE SENSOR

MA800 Rev. 1.02

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13

6/15/2018

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SPI Read Register

A read register operation is constituted of two

16-bit frames. The first frame sends a read

request which contains the 3-bit read command

(010) followed by the 5-bit register address. The

last eight bits of the frame must all be set to

zero. The second frame returns the 8-bit

register value (MSB byte).

The first 16-bit SPI frame (read request) is:

MSB

LSB

MISO

Angle(15:0)

command

reg. address

MOSI

0

1

0

A4 A3 A2 A1 A0

0 0 0 0 0 0 0 0

The second 16-bit SPI frame (response) is:

reg. value

MISO V7 V6 V5 V4 V3 V2 V1 V0

0 0 0 0 0 0 0 0

MSB

LSB

MOSI

0

See Figure 11 for a complete transmission.

For example, to get the value of the magnetic

level high and low flags (MGH and MGL), read

register 27 (bit 6, bit 7) by sending the following

first frame:

MSB

LSB

MISO

Angle(15:0)

command

reg. address

MOSI

0

1

0

1

1

0

1

1

0 0 0 0 0 0 0 0

In the second frame, the MagAlpha replies:

reg. value

MISO MGH MGL X X X X X X

0 0 0 0 0 0 0 0

MSB

LSB

MOSI

0

See Figure 12 for a complete example.

Figure 11: 16-Bit Frames Read Register Operation

Figure 12: Example Read Magnetic Level Flags High and Low (MGH, MGH) on Register 27, Bit 6 to Bit 7