Datasheet
TMC429 DATASHEET (v. 1.07 / 2012-AUG-01) 33
Copyright © 2010-2012, TRINAMIC Motion Control GmbH & Co. KG
10.5 if_configuration_429 (JDX=%0100)
The register if_configuration_429 is the interface configuration register for the TMC429. It is for
configuration of the additional reference inputs, the demultiplexed interrupt output, the step / direction
interface and for association of the position compare output signal to one stepper motor.
if_configuration_429
Function
INV_REF
invert polarity of reference switches (common polarity for all reference switches
SDO_INT
map internal non-multiplexed interrupt status to nINT_SDO_C (needs SDOZ_C as SDO_C for
read back information fomr the TMC429 to the micro controller); with SDO_INT='1' the
nINT_SDO_C is a non-multiplexed nINT output to the micro controller
STEP_HALF
toggle on each step pulse (this halfs the step frequency, both pulse edges represent steps);
this function can be used for the TMC262; STEP_HALF reduces the required step puls
bandwith and is use full if one used e.g. low-bandwidth opto couples;
INV_STP
invert step pulse polarity; this is for adaption of the step polarity to external diver stages
INV_DIR
invert step pulse polarity; this is for adaption to external diver stages; alternatively, this can be
used as a shaft bit to adjust the direction of motion for a motor, but do not use this as a
direction bit because it has no effect on the internal handling of signs (x_actual, v_actual, ....)
EN_SD
ENable StepDirection; Important Hint: The Step Pulse Timing (length) must be compatible with
step frequency; the Step Pulse Timing is determined by the 4 LSBs of CLK2_DIV for when
step/direction mode ist selected by ED_SD='1';
POS_COMP_SEL_0
select one motor out of three motors (%00, %01, %10) for the position compare function output
of the TMC429 named poscmp
POS_COMP_SEL_1
EN_REFR
enable new TMC429 reference inputs REFR1, REFR2, REFR3; EN_REFR=0 is the default; this
is important because the REFRx input have internal pull-up resistors an this might cause
trouble it these inout are not-connected (for the SSOP16 these REFRx can not be connected;
Table 10-1: TMC429 interface configuration register control bits
32 bit DATAGRAM sent from a µC to the TMC429
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9
8
7
6
5
4
3
2
1
0
RRS
ADDRESS
RW
DATA
0
smda
0
1
0
0
if_configuration_429
EN_REFR
POS_COMP_SEL_1
POS_COMP_SEL_0
EN_SD
INV_DIR
INV_STP
STEP_HALF
SDO_INT
INV_REF
Table 10-2: TMC429 interface configuration register
Hint: After PowerOn in SPI => '1' at SPI outputs (that are wired as STEP and DIRECTION)
Hint: Step-Dir-Mode429 : open inputs REFR1, REFR2, REFR3 have active state due to their internal
pull-up resistors if REFMUX=0. If EN_REFR='0' thes additional reference switch inputs are ignored.
Hint: REFMUX does NOT work in Step-Direction-Mode because the SPI signal nSCS_S is not
available because that output is signal S2 (step2) in step direction mode
Hint: Do not enable unused REFR1, REFR2, REFR3 inputs of the TMC429 as STOP switches if these
inputs are open, because they have internal pull-up resistors.