Datasheet

TMC2130 DATASHEET (Rev. 1.09 / 2017-MAY-15) 29
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5.3 SPI Mode Register
This register cannot be used in STEP/DIR mode.
SPI MODE REGISTER (0X2D)
R/W
Addr
n
Register
Description / bit names
Range [Unit]
RW
0x2D
32
XDIRECT
direct_mode
0: Normal operation
1: Directly SPI driven motor current
Direct mode operation:
XDIRECT specifies Motor coil currents and
polarity directly programmed via the serial
interface. Use signed, two’s complement
numbers.
Coil A current (bits 8..0) (signed)
Coil B current (bits 24..16) (signed)
Range: +-248 for normal operation, up to +-255
with stealthChop
In this mode, the current is scaled by IHOLD
setting. Velocity based current regulation of
voltage PWM is not available in this mode. The
automatic voltage PWM current regulation will
work only for low stepper motor velocities.
dcStep is not available in this mode. coolStep
and stallGuard only can be used, when
additionally supplying a STEP signal. This will
also enable automatic current scaling.
±255
for both coils
5.4 dcStep Minimum Velocity Register
DCSTEP MINIMUM VELOCITY REGISTER (0X33)
R/W
Addr
n
Register
Description / bit names
W
0x33
23
VDCMIN
The automatic commutation dcStep becomes enabled by the
external signal DCEN. VDCMIN is used as the minimum step
velocity when the motor is heavily loaded.
Hint: Also set DCCTRL parameters in order to operate dcStep.
time reference t for VDCMIN: t = 2^24 / f
CLK