Datasheet
TMC429 DATASHEET (v. 1.07 / 2012-AUG-01) 48
Copyright © 2010-2012, TRINAMIC Motion Control GmbH & Co. KG
MSBs of full
wave index (range)
Quadrant
PH_A (sin)
PH_B (cos)
FD_A (sin)
FD_B (cos)
%00
(0...63)
1
st
1
1
0
1
%01
(64...127)
2
nd
1
0
1
0
%10
(128...191)
3
rd
0
0
0
1
%11
(192...255)
4
th
0
1
1
0
Table 13-3: Phase Bits and Fast Decay Control Bits
Hints: One should always initialize the whole LUT to be sure to read valid wave values, even if one
changes the micro step resolution after some micro steps have been done on higher resolution. Even if
one uses e.g. 16 times microstepping, one gets a smoother move for the stepper motor if one
initializes the full sine wave LUT according to Table 13-2 Datagrams for initialization of a quarter sine
wave period microstep look-up-table on page 47 and using the MSB DAC bits (DAC_A_5, DAC_A_4,
DAC_A_3, DAC_A_2 and DAC_B_5, DAC_B_4, DAC_B_3, DAC_B_2). So, one should always
completely initialize the quarter sine wave LUT, no matter what micro step resolution is used. The
addressing starts at 0 after power-on reset only. Changing the micro step resolution after some micro
steps have been made causes an offset for the addressing that has to be taken into account for
positioning a stepper motor.
usrs
increment
width
1
st
quadrant
2
nd
quadrant
3
rd
quadrant
4
th
quadrant
%110
1
sin
0,1,2, 3, , 61, 62,63,
63, 63, 62, 61,, 3, 2,1,
0,1,2, 3, , 61, 62,63,
63, 63,62,61,, 3, 2,1
cos
63, 63, 62, 61,,2,1,
0,1,2, 3, , 61, 62,63,
63, 63,62,61,,3, 2,1,
0,1,2, 3, , 61, 62,63
%101
2
sin
0,2, 4, 6, , 58, 60,62,
63, 60, 58, 56,, 4, 2,
0,2, 4, 6, , 58, 60,62,
63, 60, 58, 56,, 4, 2
cos
63, 60, 58, 56,, 4, 2,
0,2, 4, 6, , 58, 60,62,
63, 60, 58, 56,, 4, 2,
0,2, 4, 6, , 58, 60,62
%100
4
sin
0, 4, 8, 12, , 56, 60,
63, 60, 56, , 12, 8, 4,
0, 4, 8, 12, , 56, 60,
63, 60, 56, , 12, 8, 4
cos
63, 60, 56, , 12, 8, 4,
0, 4, 8, 12, , 56, 60,
63, 60, 56, , 12, 8, 4,
0, 4, 8, 12, , 56, 60
%011
8
sin
0, 8, 16, 24, , 48, 56
63, 56, 48, 40,,16, 8,
0, 8, 16, 24, , 48, 56
63, 56, 48, 40,,16, 8
cos
63, 56, 48, 40,,16, 8,
0, 8, 16, 24, , 48, 56
63, 56, 48, 40,,16, 8,
0, 8, 16, 24, , 48, 56
%010
16
sin
0, 16, 32, 48,
63, 48, 32, 16,
0, 16, 32, 48,
63, 48, 32, 16
cos
63, 48, 32, 16,
0, 16, 32, 48,
63, 48, 32, 16,
0, 16, 32, 48
%001
(HS)
32
sin
0, 32,
63, 32,
0, 32,
63, 32
cos
63, 32,
0, 32,
63, 32
0, 32
%000
(FS)
64
sin
0,
63,
0,
63
cos
63,
0,
63
0
Table 13-4: Wave look-up table (LUT) indices for different microstep resolutions
13.2 Partial look-up table initialization option
A partially initialized micro step table may be sufficient, if all stepper motors except those driven in full
step mode are programmed to use the same micro step resolution constantly before a single micro
step is processed. But with a partial initialized micro step look-up table, the micro step resolution must
not be changed after any step is made after power-on reset. So, a partially initialized look-up table
should be taken into account only, if it is a must because of too small memory of the host
microcontroller. Instead of partial initialization of the look-up table of the TMC429, initialization with a
triangular function f
rhomb
(
) would be a better choice.