TMC51x0 Register Access and Configuration Guide

This guide provides a comprehensive overview of the TMC51x0 (TMC5130 & TMC5160) registers, their access permissions, and recommended configuration strategies. It is based on the verified driver implementation and the TMC51x0 datasheet.

1. Register Map and Access Types

The TMC51x0 registers are divided into functional groups. Each register has specific access permissions:

  • RW: Read and Write
  • R: Read-Only
  • W: Write-Only
  • RWC: Read, Write-1-to-Clear

1.1 General Configuration (0x00…0x0F)

Address Register Access Description
0x00 GCONF RW Global configuration flags (direction, PWM mode, diagnostics).
0x01 GSTAT RWC Global status flags (reset, error, UV). Write 1 to clear flags.
0x02 IFCNT R Interface transmission counter (UART only).
0x03 NODECONF W UART node address and send delay configuration.
0x04 IOIN R Reads state of all digital input pins.
0x04 OUTPUT W Sets SDO_CFG0 pin polarity (Bit 0). Same address as IOIN!
0x05 X_COMPARE W Position comparison value for position pulse output.
0x06 OTP_PROG W OTP programming register (Factory use).
0x07 OTP_READ R Reads OTP memory contents.
0x08 FACTORY_CONF RW Factory clock trim (FCLKTRIM).
0x09 SHORT_CONF W Short circuit detection sensitivity and filtering.
0x0A DRV_CONF W Driver strength, BBM time, and OT protection settings.
0x0B GLOBAL_SCALER W Global current scaling factor (32-256).
0x0C OFFSET_READ R Reads offset calibration results.

Usage Recommendations:

  • GCONF: Configure at startup. Use driver.ConfigureGlobalConfig().
  • GSTAT: Check for uv_cp (Charge Pump Undervoltage) if motor stops unexpectedly. Clear reset flag after initialization.
  • IOIN: Use driver.io.ReadInputStatus() to verify wiring (e.g., REFL/REFR switches, DRV_ENN).
  • GLOBAL_SCALER: Set to appropriate value (e.g., 160-256) to match motor current capability.

1.2 Velocity Dependent Driver Feature Control (0x10…0x1F)

Address Register Access Description
0x10 IHOLD_IRUN W Run and Hold current settings.
0x11 TPOWERDOWN W Delay before power down to stand still current.
0x12 TSTEP R Measured time between microsteps (inverse of velocity).
0x13 TPWMTHRS W Upper velocity threshold for StealthChop.
0x14 TCOOLTHRS W Lower velocity threshold for CoolStep/StallGuard.
0x15 THIGH W Velocity threshold for high-speed chopper/fullstep mode.

Usage Recommendations:

  • IHOLD_IRUN: Use driver.motorControl.SetCurrent(irun, ihold). Typical irun=16-31, ihold=0-16.
  • Thresholds: Use driver.thresholds.SetModeChangeSpeeds() to set TPWMTHRS, TCOOLTHRS, and THIGH (default unit: revolutions per second).
    • TPWMTHRS: Set typical cruising speed limit for silent operation.
    • TCOOLTHRS: Set above startup speed to enable StallGuard only when moving stably.

1.3 Ramp Generator Motion Control (0x20…0x2D)

Address Register Access Description
0x20 RAMPMODE RW 0=Positioning, 1=Vel(+), 2=Vel(-), 3=Hold.
0x21 XACTUAL RW Actual position (signed 32-bit).
0x22 VACTUAL R Actual velocity (signed 24-bit).
0x23 VSTART W Start velocity. Set > 0 (e.g., 100) to avoid jerky starts.
0x24 A1 W First acceleration (Start -> V1).
0x25 V1 W Threshold velocity for A1->AMAX transition.
0x26 AMAX W Max acceleration (standard).
0x27 VMAX W Target velocity.
0x28 DMAX W Max deceleration (standard).
0x2A D1 W Final deceleration (V1 -> Stop). Do not set to 0!
0x2B VSTOP W Stop velocity. Set >= VSTART.
0x2C TZEROWAIT W Wait time after stop before direction change.
0x2D XTARGET RW Target position (signed 32-bit).

Usage Recommendations:

  • Positioning: Set VMAX, AMAX, DMAX first, then write XTARGET to start move.
  • Velocity Mode: Use driver.rampControl.SetMaxSpeed() with positive/negative value to control direction.
  • S-Curve: For smoother motion, set V1 > 0 and use A1/D1 for start/stop phases.
  • Safety: Always ensure D1 != 0 in positioning mode.

1.4 Ramp Generator Driver Features (0x30…0x36)

Address Register Access Description
0x33 VDCMIN W Velocity threshold for DcStep commutation.
0x34 SW_MODE RW Switch stop configuration (endstops, stall stop).
0x35 RAMP_STAT RWC Ramp status flags (reached, stop event, stall).
0x36 XLATCH R Position latched on switch/stall event.

Usage Recommendations:

  • Homing: Use driver.homing.PerformSensorlessHoming() or driver.homing.PerformSwitchHoming().
  • Endstops: Configure with driver.switches.ConfigureReferenceSwitch(). Use driver.io.ReadInputStatus() to verify wiring logic (NO/NC).

1.5 Encoder Registers (0x38…0x3C)

Address Register Access Description
0x38 ENCMODE RW Encoder configuration (polarity, prescaler).
0x39 X_ENC RW Actual encoder position.
0x3A ENC_CONST W Encoder resolution matching factor.
0x3B ENC_STATUS RWC Encoder events (N-channel, deviation).
0x3C ENC_LATCH R Encoder position latched on N-event.
0x3D ENC_DEVIATION W Max deviation for warning flag.

Usage Recommendations:

  • Calibration: Use driver.encoder.SetResolution() to automatically calculate ENC_CONST.
  • Verification: Check ENC_STATUS periodically for deviation warnings if using closed loop.

1.6 Motor Driver Registers (0x60…0x7F)

Address Register Access Description
0x60..0x67 MSLUT[0..7] W Microstep lookup table entries.
0x68 MSLUTSEL W LUT segment configuration.
0x69 MSLUTSTART W Start current for LUT.
0x6A MSCNT R Microstep counter (0-1023).
0x6B MSCURACT R Actual microstep current (signed 9-bit).
0x6C CHOPCONF RW Chopper configuration (TOFF, TBL, HSTRT, HEND).
0x6D COOLCONF W CoolStep and StallGuard2 configuration.
0x6E DCCTRL W DcStep configuration.
0x6F DRV_STATUS R Driver status (StallGuard result, OT/Short flags).
0x70 PWMCONF W StealthChop PWM configuration.
0x71 PWM_SCALE R StealthChop regulator result.
0x72 PWM_AUTO R Auto-tuned PWM values.
0x73 LOST_STEPS R Lost step counter (DcStep only).

Usage Recommendations:

  • CHOPCONF: Set TOFF > 0 to enable driver. TOFF=0 disables driver.
  • DRV_STATUS: Monitor SG_RESULT for load estimation. 0 = High Load, 1023 = Low Load.
  • PWM_SCALE: Use to verify StealthChop calibration. If PWM_SCALE_AUTO is 0 or very low, calibration failed (increase standstill time).

2. Configuration Workflows

2.1 Startup Verification

Always perform a setup verification at startup to catch hardware issues early:

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3
4

// Verify IC connection and Input Pins
if (!driver.status.VerifySetup()) {
    // Handle error - check power/wiring
}

2.2 Silent Operation (StealthChop)

  1. Set GCONF.en_pwm_mode = 1.
  2. Set TPWMTHRS to a high value (e.g. 0.1 rev/s ~6 RPM, using SetStealthChopVelocityThreshold()).
  3. Crucial: Allow motor to stand still for >130ms after enabling to allow PWM_OFS_AUTO calibration.
  4. Monitor PWM_SCALE to confirm regulation is active.

2.3 High Torque / High Speed (SpreadCycle)

  1. Set GCONF.en_pwm_mode = 0.
  2. Configure CHOPCONF (TOFF, TBL, HSTRT, HEND) for your motor inductance.
  3. This mode is louder but provides dynamic torque and prevents “ runaway” calibration issues at high loads.

2.4 Sensorless Homing

  1. Configure StallGuard (COOLCONF) with SGT (Threshold).
  2. Set TCOOLTHRS low enough to cover homing speed.
  3. Call driver.homing.PerformSensorlessHoming() with a span-capped BoundsOptions (uses existing SGT threshold from motor config).
    • This internally sets SW_MODE.sg_stop = 1.
    • Moves motor until stall detected.
    • Stops and returns position.

3. Troubleshooting

  • Motor not moving: Check GSTAT.uv_cp (Undervoltage), CHOPCONF.toff (Driver Enabled?), DRV_ENN pin state.
  • Motor stalling early: Decrease acceleration (AMAX, A1). Check Run Current (IRUN).
  • StealthChop noise: Check PWM_SCALE_AUTO. If near limits (+/- 255), adjust PWM_GRAD.
  • Position loss: Check DRV_STATUS for ot (Overtemp) or s2g (Short) events which disable the bridge.

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