L9942 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
L9942 Datasheet PDF : 40 Pages
| |||
L9942
5
SPI - control and status registers
SPI - control and status registers
5.1
Register 0
Table 14. Register 0
Phase counter
Bit
12 11 10
9
Access r w r w r w r w
Reset 0
0
0
0
Name P4 P3 P2 P1
Decay mode
Slew rate Step mode DIR
8
7
6
5
4
3
2
1
0
rw rw rw rw rw rw rw rw rw
0
0
0
0
0
0
0
0
0
P0 DM2 DM1 DM0 SR1 SR0 ST1 ST0 DIR
The meaning of the different bits is as follows:
:
DIR
This bit controls direction of motor movement. DIR=1 clockwise DIR=0 counter clockwise.
ST1 ST0
00
01
10
11
This bits controls step mode of motor movement (Figure 3).
Micro-stepping
Mini-stepping
Half-stepping
Full-stepping
SR1 SR0
This bit controls slew rate of bridge switches. See also parameter Table 13
DM2 DM1 DM0
000
001
010
011
100
101
110
111
This bits controls decay mode of output current (Figure 3).
Slow decay
Mixed decay, fast decay until TMD > 4 µs
Mixed decay, fast decay until TMD > 8 µs
Mixed decay, fast decay until current undershoot Tmc =TFT +TCC
Auto decay, fast decay without delay time
Auto decay, fast decay until TMD > 4 µs
Auto decay, fast decay until TMD > 8 µs
Auto decay, fast decay until current
undershoot Tmc
Auto decay uses mixed decay automatically
to reduce current for next step if required
(see Figure 3 down right).
P4 P3 P2 P1 P0 This bits control position of motor, e.g. 00000 step angle is 0°, 01111 step angle is 180 °.
Doc ID 11778 Rev 7
23/40
Share Link: 