3.2.1 Inputs and Outputs Signals

The following table lists the input and output ports of Encoder Interface.


Signal Name	Direction	Description
reset_i	Input	Active Low Asynchronous Reset Signal
sys_clk_i	Input	System Clock
fil_trig_i	Input	Filter trigger input. A timing pulse of one clock cycle width must be provided at this input. The periodicity of the pulse determines the sampling time.
direction_config_i	Input	Direction configuration bit - used at calibration time to align the rotor. When 1, aligns rotor for counter clockwise starting or when 0, aligns rotor for clockwise starting.
clear_buffer_i	Input	Clears the filter buffer generally when the motor is stopped. A pulse of one clock cycle width must be input each time the motor stops.
sensor_reset_i	Input	Sensor Reset signal: When set to 1, rotor angle is reset to the equivalent of 90° or 270° as determined by the direction_config_i input. When set to 0 (zero), normal operation.
qa_i	Input	Encoder input A
qb_i	Input	Encoder input B
speed_factor_i	Input	Speed output scaling multiplier
angle_factor_i	Input	Angle output scaling multiplier
angle_count_max_i	Input	Maximum angle count value in terms of encoder pulse events.
speed_window_i	Input	The time window for speed computation, specified in multiples of 10 µs. Larger time window gives better speed resolution but has higher latency. Smaller time window must be used for high dynamic speed response.
filter_factor_i	Input	Filter factor value for filter – if value is n, the filter time constant is 2^n times the sampling time of the filter defined by filt_trig_i.
dir_o	Output	Direction signal generated based on encoder input signals.
speed_done_o	Output	Indicates speed computation is ready for filtering (at the end of speed window). A pulse of one sys_clk_i cycle width is generated.
speed_filter_done_o	Output	Indicates speed output after filtering is valid (at omega_out_o output port). A pulse of one sys_clk_i cycle width is generated.
omega_out_o	Output	Rotor speed output after filtering - suitable for use as speed feedback in speed control operation.
angle_out_o	Output	Electrical angle output suitable for FOC.
line_count_o	Output	Specifies the rotor position in terms of number of encoder lines (increments) since the last sensor reset. Suitable for use with position control operations.