NSC veneers for the communications drivers. More...

#include <stdint.h>
#include "ra8_err.h"
#include "ra8_i3c.h"
#include "ra8_nsc_veneer.h"
#include "ra8_sci.h"
#include "ra8_spi.h"
#include "ra8_usb.h"

Include dependency graph for ra8_nsc_comms.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Enumerations
enum	ra8_nsc_spi_pack_const_t : uint32_t { k_ra8_nsc_spi_byte_msk = 0x000000FFU , k_ra8_nsc_spi_bw_shift = 8U }
	Bit layout for ra8_nsc_spi_ch_bw() packed argument. More...

Functions
ra8_err_t	ra8_nsc_sci_init (uint8_t channel, const ra8_sci_cfg_t *cfg)
	NSC veneer: bring up an SCI channel from NS code.
ra8_err_t	ra8_nsc_sci_putc (uint8_t channel, uint8_t byte)
	NSC veneer: blocking single-byte SCI write.
ra8_err_t	ra8_nsc_sci_getc (uint8_t channel, uint8_t *out_byte)
	NSC veneer: blocking single-byte SCI read.
ra8_err_t	ra8_nsc_iic_init (uint8_t channel, const ra8_i3c_cfg_t *cfg)
	NSC veneer: bring up an IIC channel.
ra8_err_t	ra8_nsc_iic_write (uint8_t channel, uint8_t target_7b, const uint8_t *data, uint32_t len)
	NSC veneer: blocking I2C write to a 7-bit target.
ra8_err_t	ra8_nsc_iic_read (uint8_t channel, uint8_t target_7b, uint8_t *out_buf, uint32_t len)
	NSC veneer: blocking I2C read from a 7-bit target.
ra8_err_t	ra8_nsc_spi_init (uint8_t channel, const ra8_spi_cfg_t *cfg)
	NSC veneer: bring up an SPI controller channel.
ra8_err_t	ra8_nsc_spi_xfer8 (uint8_t channel, uint8_t tx, uint8_t *rx)
	NSC veneer: full-duplex single-byte SPI exchange.
ra8_err_t	ra8_nsc_spi_write (uint8_t channel, const void *tx, uint32_t len, ra8_spi_bit_width_t bit_width)
	NSC veneer: multi-frame TX-only polling SPI write.
ra8_err_t	ra8_nsc_spi_read (uint8_t channel, void *rx, uint32_t len, ra8_spi_bit_width_t bit_width)
	NSC veneer: multi-frame RX-only polling SPI read.
static uint32_t	ra8_nsc_spi_ch_bw (uint8_t channel, ra8_spi_bit_width_t bit_width)
	Pack channel + bit_width into a single 32-bit argument.
ra8_err_t	ra8_nsc_spi_write_read (uint32_t ch_bw, const void tx, void rx, uint32_t len)
	NSC veneer: multi-frame full-duplex polling SPI exchange.
ra8_err_t	ra8_nsc_usb_init (ra8_usb_speed_t speed)
	NSC veneer: bring up the USB device controller.
ra8_err_t	ra8_nsc_usb_attach (ra8_usb_speed_t speed, bool attached)
	NSC veneer: raise / drop USB D+ pull-up.

Detailed Description

NSC veneers for the communications drivers.

Tag: [Ring 4 / NSC] {World: NSC}

Retrofit veneers for the comms drivers (ra8_sci, ra8_iic, ra8_spi, ra8_usb). Each function here is a Non-Secure Callable entry point that validates pointer arguments via cmse_check_address_range (under TrustZone) and forwards to the matching Ring-3 driver primitive in the secure world.

This layer ships a representative subset – init + the most common transfer primitive per driver. The remaining surface (interrupt callbacks, DMA paths, error introspection) is straightforward to add by following the same pattern; it is deferred to land alongside the first NS-world consumer that actually exercises those paths.

Coverage

ra8_nsc_sci_init wraps ra8_sci_init ra8_nsc_sci_putc wraps ra8_sci_putc_polling ra8_nsc_sci_getc wraps ra8_sci_getc_polling ra8_nsc_iic_init wraps ra8_i3c_init ra8_nsc_iic_write wraps ra8_i3c_write ra8_nsc_iic_read wraps ra8_i3c_read ra8_nsc_spi_init wraps ra8_spi_init ra8_nsc_spi_xfer8 wraps ra8_spi_xfer8 ra8_nsc_usb_init wraps ra8_usb_device_init ra8_nsc_usb_attach wraps ra8_usb_device_attach

TrustZone Safety:

Validates: every config struct pointer + every byte buffer is in NS-readable / NS-writable memory.
Trusts: the secure-side driver state machines.
Denies: raw struct pass-by-value crossing the boundary (the cfg pointers stay opaque to the secure side until the veneer copies what it needs).

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Definition in file ra8_nsc_comms.h.

Enumeration Type Documentation

◆ ra8_nsc_spi_pack_const_t

enum ra8_nsc_spi_pack_const_t : uint32_t

Bit layout for ra8_nsc_spi_ch_bw() packed argument.

Enumerator
k_ra8_nsc_spi_byte_msk	Byte mask within the packed word.
k_ra8_nsc_spi_bw_shift	Bit position of bit_width.

Definition at line 181 of file ra8_nsc_comms.h.

Function Documentation

◆ ra8_nsc_iic_init()

ra8_err_t ra8_nsc_iic_init	(	uint8_t	channel,
		const ra8_i3c_cfg_t *	cfg )

nodiscard

NSC veneer: bring up an IIC channel.

Since: 0.1.0

NSC veneer: bring up an IIC channel.

Validates the NS pointer to cfg then forwards to ra8_i3c_init.

Parameters

[in]	channel	IIC channel index.
[in]	cfg	Caller-supplied configuration in NS memory.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Channel programmed.
k_ra8_err_null_ptr	cfg was NULL.
k_ra8_err_invalid_arg	cfg not in NS region or channel bad.

Precondition: TrustZone substrate up.; cfg lies entirely within NS data region.

Postcondition: On success the IIC hardware is ready for I/O.; On failure no module state was mutated.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. cfg is range-checked so a hostile NS pointer cannot leak secure-region bytes.

Note: Thread-safe: serialised by the secure IIC driver lock.

Since: 0.1.0

Definition at line 167 of file ra8_nsc_comms.c.

References k_ra8_i3c_mode_i2c, ra8_i3c_cfg_t::mode, RA8_CHECK_NULL_PTR, ra8_i3c_init(), RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_VENEER, and s_tag.

◆ ra8_nsc_iic_read()

ra8_err_t ra8_nsc_iic_read	(	uint8_t	channel,
		uint8_t	target_7b,
		uint8_t *	out_buf,
		uint32_t	len )

nodiscard

NSC veneer: blocking I2C read from a 7-bit target.

Since: 0.1.0

Validates [out_buf, out_buf+len) lies in writable NS memory then forwards to ra8_i3c_read.

Parameters

[in]	channel	IIC channel index.
[in]	target_7b	7-bit peripheral address.
[out]	out_buf	NS destination buffer.
[in]	len	Byte count to read.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Bytes received into out_buf.
k_ra8_err_null_ptr	out_buf was NULL.
k_ra8_err_invalid_arg	Range outside NS region.

Precondition: ra8_nsc_iic_init succeeded for channel.; [out_buf, out_buf+len) lies in NS data region.

Postcondition: On success out_buf holds len received bytes.; On failure out_buf content is undefined.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. cmse_check_address_range guarantees the secure driver only writes to NS memory.

Note: Thread-safe: serialised by the secure IIC driver lock.

Since: 0.1.0

Definition at line 244 of file ra8_nsc_comms.c.

References RA8_CHECK_NULL_PTR, ra8_i3c_read(), RA8_NSC_CHECK_NS_RANGE_RW, RA8_NSC_VENEER, and s_tag.

◆ ra8_nsc_iic_write()

ra8_err_t ra8_nsc_iic_write	(	uint8_t	channel,
		uint8_t	target_7b,
		const uint8_t *	data,
		uint32_t	len )

nodiscard

NSC veneer: blocking I2C write to a 7-bit target.

Since: 0.1.0

Validates [data, data+len) lies in NS memory then forwards to ra8_i3c_write.

Parameters

[in]	channel	IIC channel index.
[in]	target_7b	7-bit peripheral address.
[in]	data	NS source buffer.
[in]	len	Byte count.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Bytes transmitted (or ACK-checked).
k_ra8_err_null_ptr	data was NULL.
k_ra8_err_invalid_arg	Range outside NS region or len bogus.

Precondition: ra8_nsc_iic_init succeeded for channel.; [data, data+len) lies in NS data region.

Postcondition: On success the bus completed a START-WRITE-STOP transaction.; On failure the bus has been released.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. cmse_check_address_range rejects buffers that overlap secure memory before the secure driver reads them.

Note: Thread-safe: serialised by the secure IIC driver lock.

Since: 0.1.0

Definition at line 206 of file ra8_nsc_comms.c.

References RA8_CHECK_NULL_PTR, ra8_i3c_write(), RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_VENEER, and s_tag.

◆ ra8_nsc_sci_getc()

ra8_err_t ra8_nsc_sci_getc	(	uint8_t	channel,
		uint8_t *	out_byte )

nodiscard

NSC veneer: blocking single-byte SCI read.

Parameters

[in]	channel	SCI channel 0..9.
[out]	out_byte	Destination in NS memory.

Returns: ra8_err_t error code.

Since: 0.1.0

Validates out_byte is in the NS region and forwards to ra8_sci_getc_polling.

Parameters

[in]	channel	SCI channel index.
[out]	out_byte	Destination byte (in NS memory).

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	One byte stored at *out_byte.
k_ra8_err_null_ptr	out_byte was NULL.
k_ra8_err_invalid_arg	Pointer not in NS region.

Precondition: ra8_nsc_sci_init succeeded for channel.; out_byte lies in NS data region.

Postcondition: On success *out_byte reflects the received byte.; On failure *out_byte unchanged.

TrustZone:: Crosses NS->S via cmse_nonsecure_entry. out_byte is cmse_check_address_range-validated so the secure driver cannot be tricked into writing into secure memory.

Note: Thread-safe: serialised by the secure SCI driver lock.

Since: 0.1.0

Definition at line 129 of file ra8_nsc_comms.c.

References RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_RW, RA8_NSC_VENEER, ra8_sci_getc_polling(), and s_tag.

◆ ra8_nsc_sci_init()

ra8_err_t ra8_nsc_sci_init	(	uint8_t	channel,
		const ra8_sci_cfg_t *	cfg )

nodiscard

NSC veneer: bring up an SCI channel from NS code.

Parameters

[in]	channel	SCI channel 0..9.
[in]	cfg	Configuration descriptor in NS memory.

Returns: ra8_err_t error code from the underlying ra8_sci_init.

TrustZone Safety:

Validates the cfg pointer covers sizeof(ra8_sci_cfg_t) of NS-readable memory before forwarding.

Since: 0.1.0

NSC veneer: bring up an SCI channel from NS code.

Validates cfg lies inside the NS region (TZ builds) and forwards to the secure ra8_sci_init driver.

Parameters

[in]	channel	SCI channel index (0..k_ra8_sci_channel_max-1).
[in]	cfg	Caller-supplied configuration in NS memory.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Channel programmed and ready.
k_ra8_err_null_ptr	cfg was NULL.
k_ra8_err_invalid_arg	cfg outside NS range or channel bad.

Precondition: TrustZone substrate has been initialized.; cfg lies entirely within the NS data region.

Postcondition: On success the SCI hardware is ready for I/O.; On failure no module state was mutated.

TrustZone:: Crosses the NS->S boundary via cmse_nonsecure_entry. The caller pointer is checked with cmse_check_address_range so a malicious NS pointer cannot trick the secure SCI driver into reading secure memory.

Note: Thread-safe: serialised by the secure SCI driver lock.

Since: 0.1.0

Definition at line 65 of file ra8_nsc_comms.c.

References RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_VENEER, ra8_sci_init(), and s_tag.

◆ ra8_nsc_sci_putc()

ra8_err_t ra8_nsc_sci_putc	(	uint8_t	channel,
		uint8_t	byte )

nodiscard

NSC veneer: blocking single-byte SCI write.

Parameters

[in]	channel	SCI channel 0..9.
[in]	byte	Byte to send.

Returns: ra8_err_t error code.

Since: 0.1.0

Forwards directly to ra8_sci_putc_polling; no pointer crosses the boundary so no NS-range check is needed.

Parameters

[in]	channel	SCI channel index.
[in]	byte	Byte to transmit.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Byte queued for TX.
k_ra8_err_invalid_arg	Bad channel index.

Precondition: ra8_nsc_sci_init succeeded for channel.; TrustZone substrate up.

Postcondition: On success one byte was transmitted.; On failure the bus state is unchanged.

TrustZone:: Crosses NS->S via cmse_nonsecure_entry. Scalar-only signature; nothing leaks across the boundary.

Note: Thread-safe: serialised by the secure SCI driver lock.

Since: 0.1.0

Definition at line 97 of file ra8_nsc_comms.c.

References RA8_NSC_VENEER, and ra8_sci_putc_polling().

◆ ra8_nsc_spi_ch_bw()

uint32_t ra8_nsc_spi_ch_bw	(	uint8_t	channel,
		ra8_spi_bit_width_t	bit_width )

inlinestatic

Pack channel + bit_width into a single 32-bit argument.

ra8_nsc_spi_write_read would naturally have five arguments (channel, tx, rx, len, bit_width) but cmse_nonsecure_entry requires every parameter to fit in a register (AAPCS R0..R3). Five args spill to the stack and the compiler rejects the attribute. We encode channel in bits [7:0] and bit_width in bits [15:8] so the veneer takes four register-sized arguments.

Parameters

[in]	channel	SPI channel id.
[in]	bit_width	Bus bit width enum value.

Returns: Packed ch_bw value suitable for ra8_nsc_spi_write_read.

Return values

value (channel & 0xFF) | (bit_width << 8).

Precondition: None.; None.

Postcondition: Returned value round-trips: (v & 0xFF) == channel and ((v >> 8) & 0xFF) == (uint8_t)bit_width.; No side effects.

Note: Pure function; safe from any context.

Since: 0.1.0

Definition at line 212 of file ra8_nsc_comms.h.

References k_ra8_nsc_spi_bw_shift, and k_ra8_nsc_spi_byte_msk.

◆ ra8_nsc_spi_init()

ra8_err_t ra8_nsc_spi_init	(	uint8_t	channel,
		const ra8_spi_cfg_t *	cfg )

nodiscard

NSC veneer: bring up an SPI controller channel.

Since: 0.1.0

NSC veneer: bring up an SPI controller channel.

Validates the NS pointer to cfg then forwards to ra8_spi_init.

Parameters

[in]	channel	SPI channel index.
[in]	cfg	Caller-supplied configuration in NS memory.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Channel programmed.
k_ra8_err_null_ptr	cfg was NULL.
k_ra8_err_invalid_arg	cfg not in NS region or channel bad.

Precondition: TrustZone substrate up.; cfg lies in NS data region.

Postcondition: On success the SPI hardware is ready for transfers.; On failure no module state was mutated.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. cfg is range-checked prior to the secure-side read.

Note: Thread-safe: serialised by the secure SPI driver lock.

Since: 0.1.0

Definition at line 285 of file ra8_nsc_comms.c.

References RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_VENEER, ra8_spi_init(), and s_tag.

◆ ra8_nsc_spi_read()

ra8_err_t ra8_nsc_spi_read	(	uint8_t	channel,
		void *	rx,
		uint32_t	len,
		ra8_spi_bit_width_t	bit_width )

nodiscard

NSC veneer: multi-frame RX-only polling SPI read.

TrustZone Safety:

Validates rx covers len * sizeof(unit) bytes of NS-writable memory before forwarding.

Since: 0.1.0

Computes the byte span, range-checks rx in NS writable memory, then forwards to ra8_spi_read.

Parameters

[in]	channel	SPI channel index.
[out]	rx	NS destination buffer (may be NULL only if len == 0).
[in]	len	Frame count.
[in]	bit_width	Frame width (8/16/32).

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Bytes received into rx.
k_ra8_err_null_ptr	rx was NULL with non-zero len.
k_ra8_err_invalid_arg	Range outside NS region or bad width.

Precondition: ra8_nsc_spi_init succeeded for channel.; [rx, rx + bytes_per_frame*len) lies in NS writable memory.

Postcondition: On success rx holds len frames.; On failure rx content is undefined.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. rx is range-checked so the secure driver cannot be tricked into writing into secure RAM.

Note: Thread-safe: serialised by the secure SPI driver lock.

Since: 0.1.0

Definition at line 485 of file ra8_nsc_comms.c.

References internal_spi_byte_span(), internal_spi_unit_bytes(), k_ra8_err_invalid_arg, RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_RW, RA8_NSC_VENEER, ra8_spi_read(), and s_tag.

◆ ra8_nsc_spi_write()

ra8_err_t ra8_nsc_spi_write	(	uint8_t	channel,
		const void *	tx,
		uint32_t	len,
		ra8_spi_bit_width_t	bit_width )

nodiscard

NSC veneer: multi-frame TX-only polling SPI write.

TrustZone Safety:

Validates tx covers len * sizeof(unit) bytes of NS-readable memory before forwarding.

Since: 0.1.0

Computes bytes_per_frame * len, range-checks the source buffer in NS memory, then forwards to ra8_spi_write.

Parameters

[in]	channel	SPI channel index.
[in]	tx	NS source buffer (may be NULL only if len == 0).
[in]	len	Frame count.
[in]	bit_width	Frame width (8/16/32).

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Bytes shifted out.
k_ra8_err_null_ptr	tx was NULL with non-zero len.
k_ra8_err_invalid_arg	Range outside NS region or bad width.

Precondition: ra8_nsc_spi_init succeeded for channel.; [tx, tx + bytes_per_frame*len) lies in NS memory.

Postcondition: On success len frames were transmitted.; On failure no module state was mutated.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. The full byte range spanned by len frames is cmse_check_address_range-validated so the secure driver only reads NS memory.

Note: Thread-safe: serialised by the secure SPI driver lock.

Since: 0.1.0

Definition at line 437 of file ra8_nsc_comms.c.

References internal_spi_byte_span(), internal_spi_unit_bytes(), k_ra8_err_invalid_arg, RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_VENEER, ra8_spi_write(), and s_tag.

◆ ra8_nsc_spi_write_read()

ra8_err_t ra8_nsc_spi_write_read	(	uint32_t	ch_bw,
		const void *	tx,
		void *	rx,
		uint32_t	len )

nodiscard

NSC veneer: multi-frame full-duplex polling SPI exchange.

The veneer takes four register-sized arguments; pack channel and bit_width into ch_bw with ra8_nsc_spi_ch_bw().

TrustZone Safety:

Validates both buffer ranges are NS-accessible for the requested direction before forwarding.

Since: 0.1.0

Definition at line 505 of file ra8_nsc_comms.c.

References internal_spi_byte_span(), internal_spi_unit_bytes(), k_ra8_err_invalid_arg, k_ra8_nsc_spi_bw_shift, k_ra8_nsc_spi_byte_msk, RA8_CHECK_NULL_PTR, RA8_NSC_CHECK_NS_RANGE_R, RA8_NSC_CHECK_NS_RANGE_RW, RA8_NSC_VENEER, ra8_spi_write_read(), and s_tag.

◆ ra8_nsc_spi_xfer8()

ra8_err_t ra8_nsc_spi_xfer8	(	uint8_t	channel,
		uint8_t	tx,
		uint8_t *	rx )

nodiscard

NSC veneer: full-duplex single-byte SPI exchange.

Since: 0.1.0

Forwards to ra8_spi_xfer8. rx may be NULL (matches the legacy ra8_spi_xfer8 contract); when non-NULL it is range- checked.

Parameters

[in]	channel	SPI channel index.
[in]	tx	Byte to transmit.
[out]	rx	Optional NS destination for the received byte.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Exchange complete.
k_ra8_err_invalid_arg	rx non-NULL but outside NS region.

Precondition: ra8_nsc_spi_init succeeded for channel.; rx is NULL or in NS data region.

Postcondition: On success and rx non-NULL, *rx reflects the CIPO byte.; On failure the bus state is restored.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. rx (when non-NULL) is cmse_check_address_range-validated.

Note: Thread-safe: serialised by the secure SPI driver lock.

Since: 0.1.0

Definition at line 319 of file ra8_nsc_comms.c.

References RA8_NSC_CHECK_NS_RANGE_RW, RA8_NSC_VENEER, and ra8_spi_xfer8().

◆ ra8_nsc_usb_attach()

ra8_err_t ra8_nsc_usb_attach	(	ra8_usb_speed_t	speed,
		bool	attached )

nodiscard

NSC veneer: raise / drop USB D+ pull-up.

Since: 0.1.0

NSC veneer: raise / drop USB D+ pull-up.

Forwards to ra8_usb_device_attach.

Parameters

[in]	speed	Negotiated USB speed enum.
[in]	attached	True to assert pull-up, false to release.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	Pull-up state set.
k_ra8_err_invalid_arg	Unknown speed.

Precondition: ra8_nsc_usb_init succeeded.; TrustZone substrate up.

Postcondition: On success the device is visible (or invisible) on the bus.; On failure the pull-up state is unchanged.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. Scalar arguments only.

Note: Thread-safe: no.

Since: 0.1.0

Definition at line 589 of file ra8_nsc_comms.c.

References RA8_NSC_VENEER, and ra8_usb_device_attach().

Referenced by internal_usb_audio_usb_or_halt().

◆ ra8_nsc_usb_init()

ra8_err_t ra8_nsc_usb_init ( ra8_usb_speed_t speed )

nodiscard

NSC veneer: bring up the USB device controller.

Since: 0.1.0

Forwards to ra8_usb_device_init. Scalar-only signature, so no NS-range check is needed.

Parameters

[in] speed Negotiated USB speed enum.

Returns: ra8_err_t outcome.

Return values

k_ra8_ok	USB controller programmed.
k_ra8_err_invalid_arg	Unknown speed.

Precondition: TrustZone substrate up.; USB clock tree was enabled by ra8_nsc_periph_init.

Postcondition: On success the device controller is in the powered, detached state.; On failure no module state was mutated.

TrustZone:: NS->S boundary via cmse_nonsecure_entry. Scalar enum argument; nothing crosses the boundary that needs range-checking.

Note: Thread-safe: no – USB bring-up is single-threaded.

Since: 0.1.0

Definition at line 561 of file ra8_nsc_comms.c.

References RA8_NSC_VENEER, and ra8_usb_device_init().

Enumerations

Functions

Detailed Description

Coverage

Enumeration Type Documentation

◆ ra8_nsc_spi_pack_const_t

Function Documentation

◆ ra8_nsc_iic_init()

◆ ra8_nsc_iic_read()

◆ ra8_nsc_iic_write()

◆ ra8_nsc_sci_getc()

◆ ra8_nsc_sci_init()

◆ ra8_nsc_sci_putc()

◆ ra8_nsc_spi_ch_bw()

◆ ra8_nsc_spi_init()

◆ ra8_nsc_spi_read()

◆ ra8_nsc_spi_write()

◆ ra8_nsc_spi_write_read()

◆ ra8_nsc_spi_xfer8()

◆ ra8_nsc_usb_attach()

◆ ra8_nsc_usb_init()