
TMC222 DATASHEET (V. 1.12 / March 7, 2011)
21
Copyright 2004-2009 TRINAMIC Motion Control GmbH & Co. KG
5.2.3
OTP Memory Structure
The table below shows where the OTP parameters are stored in the OTP memory.
Note: If the OTP memory has not been programmed, or if the RAM has not be programmed by a
SetMotorParam command, or if anyhow <VddReset> = ‘1’, any positioning command will be ignored, in
order to avoid any consequence due to unwanted RAM content. Please check that the correct supply
voltage is applied to the circuit before zapping the OTP (See: Table 21: DC Parameters Supply and
Voltage regulator on page 45), otherwise the circuit will be destroyed.
OTP
Address
OTP Bit Order
7
6
5
4
3
2
1
0
0x00
OSC3
OSC2
OSC1
OSC0
IREF3
IREF2
IREF1
IREF0
0x01
TSD2
TSD1
TSD0
BG3
BG2
BG1
BG0
0x02
AD3
AD2
AD1
AD0
0x03
Irun3
Irun2
Irun1
Irun0
Ihold3
Ihold2
Ihold1
Ihold0
0x04
Vmax3
Vmax2
Vmax1
Vmax0
Vmin3
Vmin2
Vmin1
Vmin0
0x05
SecPos10.
SecPos9
SecPos8
Shaft
Acc3
Acc2
Acc1
Acc0
0x06
SecPos7
SecPos6
SecPos5
SecPos4
SecPos3
SecPos2
SecPos1
SecPos0
0x07
StepMode1
StepMode0
LOCKBT
LOCKBG
Table 9 : OTP Memory Structure
Parameters stored at address 0x00 and 0x01 and bit LOCKBT are already programmed in the OTP
memory at circuit delivery, they correspond to the calibration of the circuit and are just documented
here as an indication. These might vary between different components. These bits (gray within Table 9
: OTP Memory Structure) should not be used after readout. Each OPT bit is at ‘0’ when not zapped.
Zapping a bit will set it to ‘1’. Thus only bits having to be at ‘1’ must be zapped. Zapping of a bit already
at ‘1’ is disabled, to avoid any damage of the Zener diode. It is important to note that only one single
OTP byte can be programmed at the same time (see command SetOTPParam).
Once OTP programming is completed, bit LOCKBG can be zapped, to disable unwanted future
zapping, otherwise any OTP bit at ‘0’ could still be zapped.
Lock bit
Protected byte
LOCKBT
(zapped before delivery)
0x00 to 0x01
LOCKBG
0x02 to 0x07
Table 10 : OTP Lock bits
The command used to load the application parameters via the serial bus into the RAM prior to an OTP
Memory programming is SetMotorParam. This allows for a functional verification before using a
SetOTPParam command to program and zap separately one OTP memory byte. A GetOTPParam
command issued after each SetOTPParam command allows to verify the correct byte zapping.
5.3
Stepper Motor Driver
The StepMode parameter in SetMotorParam command (6.8.9 SetMotorParam on page 34) is used to
select between different stepping modes. Following modes are available:
StepMode parameter
Mode
00
Half Stepping
01
1/4 Stepping
10
1/8 Stepping
11
1/16 Stepping
Table 11: StepMode