AMIS-30624 Datasheet, PDF (18/56 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30624
14.1.3. Position Periodicity
Depending on the stepping mode the position can range from –4096 to +4095 in half-step to –32768 to +32767 in 1/16^th micro-stepping
mode. One can project all these positions lying on a circle. When executing the command SetPosition, the position controller will
set the movement direction in such a way that the traveled distance is at a minimum.
Figure 9 illustrates that the moving direction going from ActPos = +30000 to TagPos = –30000 is clockwise.
If a counter clockwise motion is required in this example, several consecutive SetPosition commands can be used. For larger
movements, one could also use the command RunVelocity.
+10000
0
+20000
ActPos = +30000
Motion direction
-10000
TagPos = -30000
-20000
Figure 9: Motion Direction is Function on Difference Between ActPos and TagPos
14.1.4. Hardwired Address HW
In Figure 10 a simplified schematic diagram is shown of the HW comparator circuit.
The HW pin is sensed via two switches S_TOP and S_BOT. The DriveHS and DriveLS control lines are alternatively closing S_TOP and S_BOT ,
connecting HW pin with a current to resistor converter. Closing S_TOP (DriveHS = 1) will sense a current to GND. In that case the top IÆ
R converter output is low, via the closed passing switch S_{PASS_T} this signal is fed to the “R” comparator which output HW_Cmp is high.
Closing bottom switch S_BOT (DriveLS = 1) will sense a current to VBAT. The corresponding IÆ R converter output is low and via S_{PASS_B}
fed to the comparator. The output HW_Cmp will be high.
IÎ R
S_{PASS_T}
HW ^S_TOP
S_BOT
DriveHS
DriveLS
LOGIC
64 ms
Debouncer
State
High
Low
Float
1 = R2GND 2 = R2VBAT 3 = OPEN
IÎ R
S_{PASS_B}
R_th
"R"-Comp
COMP
32 μs
Debouncer
HW_Cmp
Figure 10: Simplified Schematic Diagram of the HW Comparator
PC20060926.1
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