Datasheet

22 TMC223 DATASHEET (V. 1.00 / May 3rd, 2007)

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 26: DC Parameters Supply and

Voltage regulator on page 50), otherwise the circuit will be destroyed.

OTP Bit OrderOTP

Address

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 AbsThr3 AbsThr2 AbsThr1 AbsThr0 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

0x07 DelThr3 DelThr2 DelThr1 DelThr0 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. 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 35) is used to

select between different stepping modes. Following modes are available:

StepMode parameter Mode

00 Half Stepping

01 1/4 µStepping

10 1/8 µStepping

11 1/16 µStepping

Table 11: StepMode