AMIS-30624 I2C Microstepping Motordriver
Data Sheet
SetPosition
This command is provided to the circuit by the I2C master to drive the motor to a given absolute position. See Positioning for more
details. The priority encoder table (see Priority Encoder) acknowledges the cases where a SetPositioncommand will be ignored.
SetPositioncorresponds to the following I2C command frame:
SetPosition Command Frame
Byte
Content
Structure
Bit 4
Bit 7
Bit 6
Bit 5
Bit 3
OTP1
1
1
1
Bit 2
OTP0
0
1
1
Bit 1
HW
1
1
1
Bit 0
0
1
2
3
4
5
Address
Command
Data 1
Data 2
Data 3
1
1
1
1
1
0
1
1
OTP3
OTP2
0
1
1
1
0
1
1
0
1
1
Pos[15:8]
Pos[7:0]
Data 4
Where:
Pos [15:0]Signed 16-bit position set-point for motor.
SoftStop
This command will be internally triggered when the chip temperature rises above the thermal shutdown threshold (see Table 5 and
Section 15.2.5). It provokes an immediate deceleration to Vmin(see Minimum Velocity) followed by a stop, regardless of the position
reached. Once the motor is stopped, TagPosregister is overwritten with value in ActPosregister to ensure keeping the stop position.
The I2C Master for some safety reasons can also issue a SoftStop command.
SoftStopcorresponds to the following I2C command frame:
SoftStop Command Frame
Byte
Content
Structure
Bit 7
1
1
Bit 6
1
0
Bit 5
OTP3
0
Bit 4
OTP2
0
Bit 3
OTP1
1
Bit 2
OTP0
1
Bit 1
HW
1
Bit 0
0
1
0
1
Address
Command
TestBemf
This command is provided to the circuit by the I2C master in order to output the Bemf integrator output to the SWI output of the chip.
Once activated, it can be stopped only after POR. During the Bemf observation, reading of the SWI state is internally forbidden.
TestBemfcorresponds to the following I2C command frame:
TestBemf Command Frame
Byte
Content
Structure
Bit 4
OTP2
Bit 7
1
1
Bit 6
1
0
Bit 5
OTP3
0
Bit 3
OTP1
1
Bit 2
OTP0
1
Bit 1
HW
1
Bit 0
0
1
0
1
Address
Command
1
AMI Semiconductor – Apr. 2007, Rev 3.1, M-20664-003
51
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