Introduction

Here is the list of APIs used for Nikon A-Format encoder communication protocol

Functions
int32_t	nikon_command_wait (struct nikon_priv *priv)
	Wait till PRU finishes Nikon transaction. More...

int32_t	nikon_get_pos (struct nikon_priv *priv, int8_t cmd)
	Get single cycle Nikon position data. More...

void	nikon_config_clock (struct nikon_priv priv, struct nikon_clk_cfg clk_cfg)
	Configure Nikon clock. More...

struct nikon_priv *	nikon_init (PRUICSS_Handle gPruIcssXHandle, int32_t slice, float_t frequency, uint32_t core_clk_freq, uint32_t uart_clk_freq, uint32_t mask, uint32_t totalch)
	Initialize Nikon firmware interface address and get the pointer to struct nikon_priv instance. More...

void	nikon_config_clr_cfg0 (struct nikon_priv *priv)
	Clear the channel specific frame size cfg registers. More...

int32_t	nikon_calc_clock (struct nikon_priv priv, struct nikon_clk_cfg clk_cfg)
	Calculate Rx and Tx divisors for given frequency. More...

void	nikon_generate_cdf (struct nikon_priv *priv, int32_t cmd)
	Generate CDF command to be passed in Tx fifo. More...

int32_t	nikon_reverse_bits (uint64_t bits, int32_t num_bits)
	Reverse the bits (LSB to be sent out first) provided as parameters. More...

uint32_t	nikon_calc_3bitcrc (struct nikon_priv *priv, uint32_t cmd)
	Calculate 3 bit otf crc and generate tx command. More...

void	nikon_config_load_share (struct nikon_priv *priv, int32_t mask)
	Configure Load Share mode for Nikon receiver. More...

void	nikon_config_periodic_trigger (struct nikon_priv *priv)
	Configure periodic trigger operation mode. More...

void	nikon_config_host_trigger (struct nikon_priv *priv)
	Configure host trigger operation mode. More...

int32_t	nikon_wait_for_encoder_detection (struct nikon_priv *priv)
	Detect whether the connected encoder is of selected frequency. More...

void	nikon_update_enc_len (struct nikon_priv *priv, uint32_t num_encoders, uint32_t single_turn_len[], uint32_t multi_turn_len[], uint32_t ch)
	Update number of encoders connected in bus or one-to-one and update data lengths of those encoders. More...

void	nikon_update_clock_freq (struct nikon_priv *priv, float_t frequency)
	Update the operating baud rate as user speciefied baud rate through UART menu. More...

uint32_t	nikon_get_current_channel (struct nikon_priv *priv, uint32_t ch_idx)
	Retrives the current channel in use. More...

uint32_t	nikon_get_totalchannels (struct nikon_priv *priv)
	Retrives total number of channels configured. More...

void	nikon_update_enc_addr (struct nikon_priv *priv, uint32_t enc_addr, uint32_t ls_ch)
	Update encoder address as specified by the user. More...

void	nikon_update_eeprom_addr (struct nikon_priv *priv, uint32_t addr)
	Access encoder's EEPROM location specified by the user. More...

void	nikon_update_eeprom_data (struct nikon_priv *priv, uint32_t data_high, uint32_t data_low)
	Write data at specified EEPROM location. More...

void	nikon_update_id_code (struct nikon_priv *priv, uint32_t data_high, uint32_t data_mid, uint32_t data_low)
	Assign the specified 24bits as Identification code of encoder. More...

Function Documentation

◆ nikon_command_wait()

int32_t nikon_command_wait ( struct nikon_priv * priv )

Wait till PRU finishes Nikon transaction.

Parameters

[in] priv cookie returned by nikon_init

◆ nikon_get_pos()

int32_t nikon_get_pos	(	struct nikon_priv *	priv,
		int8_t	cmd
	)

Get single cycle Nikon position data.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	cmd	command code specified by user

◆ nikon_config_clock()

void nikon_config_clock	(	struct nikon_priv *	priv,
		struct nikon_clk_cfg *	clk_cfg
	)

Configure Nikon clock.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	clk_cfg	pointer to structure containing clock configuration data

◆ nikon_init()

struct nikon_priv* nikon_init	(	PRUICSS_Handle	gPruIcssXHandle,
		int32_t	slice,
		float_t	frequency,
		uint32_t	core_clk_freq,
		uint32_t	uart_clk_freq,
		uint32_t	mask,
		uint32_t	totalch
	)

Initialize Nikon firmware interface address and get the pointer to struct nikon_priv instance.

Parameters

[in]	gPruIcssXHandle	Nikon firmware interface address
[in]	slice	ICSS PRU SLICE
[in]	frequency	Input frequency
[in]	core_clk_freq	Core clock frequency
[in]	uart_clk_freq	Uart clock frequency
[in]	mask	Mask for the selected channels
[in]	totalch	Total number of selected channels

Return values

priv	pointer to struct nikon_priv instance

◆ nikon_config_clr_cfg0()

void nikon_config_clr_cfg0 ( struct nikon_priv * priv )

Clear the channel specific frame size cfg registers.

Parameters

[in] priv cookie returned by nikon_init

◆ nikon_calc_clock()

int32_t nikon_calc_clock	(	struct nikon_priv *	priv,
		struct nikon_clk_cfg *	clk_cfg
	)

Calculate Rx and Tx divisors for given frequency.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	clk_cfg	pointer to structure containing clock configuration data.

◆ nikon_generate_cdf()

void nikon_generate_cdf	(	struct nikon_priv *	priv,
		int32_t	cmd
	)

Generate CDF command to be passed in Tx fifo.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	cmd	command code requested by the user.

◆ nikon_reverse_bits()

int32_t nikon_reverse_bits	(	uint64_t	bits,
		int32_t	num_bits
	)

Reverse the bits (LSB to be sent out first) provided as parameters.

Parameters

[in]	bits	field to be reversed as specified by the user.
[in]	num_bits	width of field to be reversed.

Return values

res	return the reversed field.

◆ nikon_calc_3bitcrc()

uint32_t nikon_calc_3bitcrc	(	struct nikon_priv *	priv,
		uint32_t	cmd
	)

Calculate 3 bit otf crc and generate tx command.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	cmd	cdf or mdf command to be included in 3 bit crc calculation.

◆ nikon_config_load_share()

void nikon_config_load_share	(	struct nikon_priv *	priv,
		int32_t	mask
	)

Configure Load Share mode for Nikon receiver.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	mask	channel mask

◆ nikon_config_periodic_trigger()

void nikon_config_periodic_trigger ( struct nikon_priv * priv )

Configure periodic trigger operation mode.

Parameters

[in] priv cookie returned by nikon_init

◆ nikon_config_host_trigger()

void nikon_config_host_trigger ( struct nikon_priv * priv )

Configure host trigger operation mode.

Parameters

[in] priv cookie returned by nikon_init

◆ nikon_wait_for_encoder_detection()

int32_t nikon_wait_for_encoder_detection ( struct nikon_priv * priv )

Detect whether the connected encoder is of selected frequency.

Parameters

[in] priv cookie returned by nikon_init

◆ nikon_update_enc_len()

void nikon_update_enc_len	(	struct nikon_priv *	priv,
		uint32_t	num_encoders,
		uint32_t	single_turn_len[],
		uint32_t	multi_turn_len[],
		uint32_t	ch
	)

Update number of encoders connected in bus or one-to-one and update data lengths of those encoders.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	num_encoders	number of encoders connected to each channel
[in]	single_turn_len	Encoder's single turn resolution
[in]	multi_turn_len	Encoder's multi turn resolution
[in]	ch	channel in use

◆ nikon_update_clock_freq()

void nikon_update_clock_freq	(	struct nikon_priv *	priv,
		float_t	frequency
	)

Update the operating baud rate as user speciefied baud rate through UART menu.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	frequency	frequency as specified by the user

◆ nikon_get_current_channel()

uint32_t nikon_get_current_channel	(	struct nikon_priv *	priv,
		uint32_t	ch_idx
	)

Retrives the current channel in use.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	ch_idx	index of current channel to be selected

Return values

channel[ch_idx] current channel in use

◆ nikon_get_totalchannels()

uint32_t nikon_get_totalchannels ( struct nikon_priv * priv )

Retrives total number of channels configured.

Parameters

[in] priv cookie returned by nikon_init

Return values

totalchannels total number of channels configured

◆ nikon_update_enc_addr()

void nikon_update_enc_addr	(	struct nikon_priv *	priv,
		uint32_t	enc_addr,
		uint32_t	ls_ch
	)

Update encoder address as specified by the user.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	enc_addr	encoder address specified by the user
[in]	ls_ch	channel in use in load share

◆ nikon_update_eeprom_addr()

void nikon_update_eeprom_addr	(	struct nikon_priv *	priv,
		uint32_t	addr
	)

Access encoder's EEPROM location specified by the user.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	addr	EEPROM address specified by the user

◆ nikon_update_eeprom_data()

void nikon_update_eeprom_data	(	struct nikon_priv *	priv,
		uint32_t	data_high,
		uint32_t	data_low
	)

Write data at specified EEPROM location.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	data_high	upper byte of data to write at EEPROM location
[in]	data_low	lower byte of data to write at EEPROM location

◆ nikon_update_id_code()

void nikon_update_id_code	(	struct nikon_priv *	priv,
		uint32_t	data_high,
		uint32_t	data_mid,
		uint32_t	data_low
	)

Assign the specified 24bits as Identification code of encoder.

Parameters

[in]	priv	cookie returned by nikon_init
[in]	data_high	Upper byte to assign as ID code[23 : 16]
[in]	data_mid	Middle byte to assign as ID code[15 : 8]
[in]	data_low	Lower byte to assign as ID code[7 : 0]

Introduction

Functions

Function Documentation

◆ nikon_command_wait()

◆ nikon_get_pos()

◆ nikon_config_clock()

◆ nikon_init()

◆ nikon_config_clr_cfg0()

◆ nikon_calc_clock()

◆ nikon_generate_cdf()

◆ nikon_reverse_bits()

◆ nikon_calc_3bitcrc()

◆ nikon_config_load_share()

◆ nikon_config_periodic_trigger()

◆ nikon_config_host_trigger()

◆ nikon_wait_for_encoder_detection()

◆ nikon_update_enc_len()

◆ nikon_update_clock_freq()

◆ nikon_get_current_channel()

◆ nikon_get_totalchannels()

◆ nikon_update_enc_addr()

◆ nikon_update_eeprom_addr()

◆ nikon_update_eeprom_data()

◆ nikon_update_id_code()