AMIS-30521 AMI Semiconductor, Inc., AMIS-30521 Datasheet - Page 12

• Manufacturer Part Number: AMIS-30521
• Description: Micro-stepping Motor Driver
• Manufacturer: AMI Semiconductor, Inc.

AMIS-30521 Micro-stepping Motor Driver
8.3.4. Translator Position
The translator position can be read in
Table 10: Circular Translator
8.3.5. Synchronization of Step Mode and NXT Input
When step mode is re-programmed to another resolution
the first arriving “NXT” input. If the micro-stepping resolution is increased (see
nearest micro-step, according to the fixed grid of the increased resolution. If however the micro-stepping resolution is decreased, then it
is possible to introduce an offset (or phase shift) in the micro-step translator table.
If the step resolution is decreased at a translator table position that is shared both by the old and new resolution setting, then the offset
is zero and micro-stepping is proceeds according to the translator table.
If the translator position is not shared both by the old and new resolution setting, then the micro-stepping proceeds with an offset
relative to the translator table (See Figure 10 right hand side).
AMI Semiconductor – June 2007, M-20683-001
www.amis.com
Note:
It is advised to reduce the micro-stepping resolution only at micro-step positions that overlap with desired micro-step positions of the new resolution.
Left: Change from lower to higher resolution. The left-hand side depicts the ending half-step position during which a new step mode
Right: Change from higher to lower resolution. The left-hand side depicts the ending micro-step position during which a new step mode
resolution was programmed. The right-hand side diagram shows the effect of subsequent NXT commands on the micro-step position.
resolution was programmed. The right-hand side diagram shows the effect of subsequent NXT commands on the half-step position.
Halfstep
Change from lower to higher resolution
Iy
endpos
Table. The translator position is updated immediately following a NXT trigger.
DIR
NXT
Ix
NXT4
Table 30: SPI Status Register
NXT3
Translator Position
1/4
NXT2
th
Update
Figure 10: Translator Position Timing Diagram
Iy
step
Figure 11: NXT-Step Mode Synchronization
NXT1
startpos
DIR
(Table 13: SPI Control Register
Ix
12
3. This is a 7-bit number equivalent to the 1/32
Translator Position
1/8
Change from higher to lower resolution
Update
Figure
th
Iy
step
endpos
11) then the coil currents will be regulated to the
0), then this is put in effect immediately upon
DIR
Ix
PC20070604.4
NXT3
NXT2
NXT1
Halfstep
Iy
startpos
PC20070604.6
th
Data Sheet
DIR
micro-step from
Ix