Serial Sound Interface Enhanced (SSIE / I2S) peripheral-block model. More...

#include <stdint.h>
#include <stdio.h>
#include "board_console.h"
#include "board_periph_block.h"
#include "emu_host_io_internal.h"

Include dependency graph for board_periph_ssie.c:

Data Structures
struct	ssie_state_t
	One SSIE channel: a flat register shadow + a TX sample tally. More...

Enumerations
enum	ssie_console_t : uint32_t { k_ssie_console_line_cap = 48U }
	Console-tap line buffer capacity for an I2S/SSIE summary. More...
enum	ssie_map_t : uint64_t { k_ssie_base = 0x4025D000UL , k_ssie_stride = 0x100UL , k_ssie_count = 2UL , k_ssie_span = 0x100UL * 2UL , k_ssie_regs = 0x40UL }
	SSIE block geometry (ra8_ssie_regs.h). More...
enum	ssie_off_t : uint64_t { k_ssie_off_ssicr = 0x00UL , k_ssie_off_ssisr = 0x04UL , k_ssie_off_ssifcr = 0x10UL , k_ssie_off_ssifsr = 0x14UL , k_ssie_off_ssiftdr = 0x18UL , k_ssie_off_ssifrdr = 0x1CUL }
	Per-channel register byte offsets (ra8_ssie_regs.h). More...
enum	ssie_field_t : uint32_t { k_ssie_ren_ten = 0x00000003U , k_ssie_iirq = 0x02000000U , k_ssie_tde = 0x00010000U }
	SSICR / SSISR / SSIFSR field masks used by the model. More...
enum	ssie_order_t : uint32_t { k_ssie_block_order = 130U }
	Per-tick order slot for the SSIE block (relative order only). More...

Functions
static RA8_INTERNAL void	internal_ssie_reset (void)
	Reset all SSIE channel shadows to power-on (zeroed) state.
static RA8_INTERNAL uint64_t	internal_ssie_read (uc_engine *uc, uint64_t addr, unsigned size)
	MMIO read inside the SSIE window: route to the addressed channel.
static RA8_INTERNAL void	internal_ssie_write (uc_engine *uc, uint64_t addr, unsigned size, uint64_t value)
	MMIO write inside the SSIE window: route to the addressed channel.
static RA8_INTERNAL void	internal_ssie_report (void)
	End-of-run SSIE section: per-channel enable state + TX tally.
static RA8_INTERNAL void	internal_ssie_block_register (void)
	Register the SSIE block before main (host constructor).

Variables
static ssie_state_t	s_ssie [k_ssie_count]
static const board_periph_block_t	s_k_ssie_block
	SSIE block descriptor (self-registered with the core).

Detailed Description

Serial Sound Interface Enhanced (SSIE / I2S) peripheral-block model.

Models the RA8D2 SSIE (ra8_ssie_regs.h, ra8_ssie.c) closely enough that the ssie_audio_loop example runs on the emulator instead of bailing to its panic-halt. Two channels (SSIE0 0x4025D000, SSIE1 0x4025D100, 0x100 stride) are modelled as a per-channel register shadow with two read overrides that the driver's bring-up actually depends on:

SSISR.IIRQ (idle, bit 25). ra8_ssie_start refuses to set REN/TEN unless it first reads SSISR with IIRQ asserted (otherwise k_ra8_err_busy). The model returns IIRQ set while the channel is idle (REN and TEN both clear) and clears it once REN/TEN are set, exactly as the real idle flag behaves, so the start sequence proceeds.
SSIFSR.TDE (transmit FIFO empty, bit 16). Held set so the transmit path always has room; ra8_ssie_write_sample writes SSIFTDR, which the model drains (counting samples for the end-of-run report) rather than backing up.

Every other register is a faithful write/readback shadow, so a "configure then verify" read returns what was written (SSICR config, SSIFCR FIFO control, SSIRST, SSIOFR audio format). The model does not synthesise audio clocks or the I2S frame – it reproduces the controller handshake the firmware drives, matching the rest of board_periph (it validates "does the firmware program the SSIE correctly", not silicon timing).

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

Since: 0.1.0

Definition in file board_periph_ssie.c.

Enumeration Type Documentation

◆ ssie_console_t

enum ssie_console_t : uint32_t

Console-tap line buffer capacity for an I2S/SSIE summary.

Enumerator
k_ssie_console_line_cap	Max chars in an "I2S ch.. tx=.." line.

Definition at line 42 of file board_periph_ssie.c.

◆ ssie_field_t

enum ssie_field_t : uint32_t

SSICR / SSISR / SSIFSR field masks used by the model.

Enumerator
k_ssie_ren_ten	SSICR REN \| TEN.
k_ssie_iirq	SSISR IIRQ idle-mode flag (bit 25).
k_ssie_tde	SSIFSR TDE transmit-FIFO-empty.

Definition at line 66 of file board_periph_ssie.c.

◆ ssie_map_t

enum ssie_map_t : uint64_t

SSIE block geometry (ra8_ssie_regs.h).

Enumerator
k_ssie_base	SSIE0 base.
k_ssie_stride	Bytes per SSIE channel.
k_ssie_count	SSIE0, SSIE1.
k_ssie_span	Ssie span.
k_ssie_regs	Shadowed 32-bit words per channel (0x00..0xFC).

Definition at line 47 of file board_periph_ssie.c.

◆ ssie_off_t

enum ssie_off_t : uint64_t

Per-channel register byte offsets (ra8_ssie_regs.h).

Enumerator
k_ssie_off_ssicr	Control (REN/TEN, MST, DWL, SWL ...).
k_ssie_off_ssisr	Status (IIRQ + over/underflow flags).
k_ssie_off_ssifcr	FIFO control (RFRST/TFRST ...).
k_ssie_off_ssifsr	FIFO status (RDF, TDE, RDC, TDC).
k_ssie_off_ssiftdr	Transmit FIFO data.
k_ssie_off_ssifrdr	Receive FIFO data.

Definition at line 56 of file board_periph_ssie.c.

◆ ssie_order_t

enum ssie_order_t : uint32_t

Per-tick order slot for the SSIE block (relative order only).

Enumerator
k_ssie_block_order	After the existing blocks; report order.

Definition at line 73 of file board_periph_ssie.c.

Function Documentation

◆ internal_ssie_block_register()

RA8_INTERNAL void internal_ssie_block_register ( void )

static

Register the SSIE block before main (host constructor).

Definition at line 228 of file board_periph_ssie.c.

References board_periph_register_block(), RA8_INTERNAL, and s_k_ssie_block.

◆ internal_ssie_read()

RA8_INTERNAL uint64_t internal_ssie_read	(	uc_engine *	uc,
		uint64_t	addr,
		unsigned	size )

static

MMIO read inside the SSIE window: route to the addressed channel.

MMIO read inside the ssie window: route to the addressed channel; this step is contained within the board periph SSIE model and uses bounded caller or module-owned storage.

Parameters

[in,out]	uc	Unicorn engine whose emulated state is read or updated.
[in]	addr	Guest address involved in the operation.
[in]	size	Size of the requested region or access in bytes.

Returns: The SSIE read result produced by the board periph SSIE model.

Return values

value The operation-specific SSIE read value.

Precondition: Arguments satisfy the ranges documented for SSIE read.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board periph SSIE model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Note: The operation is synchronous and does not transfer heap ownership.

Since: 0.1.0

Definition at line 116 of file board_periph_ssie.c.

References k_ssie_base, k_ssie_count, k_ssie_iirq, k_ssie_off_ssicr, k_ssie_off_ssifrdr, k_ssie_off_ssifsr, k_ssie_off_ssisr, k_ssie_regs, k_ssie_ren_ten, k_ssie_stride, k_ssie_tde, RA8_INTERNAL, ssie_state_t::reg, and s_ssie.

◆ internal_ssie_report()

RA8_INTERNAL void internal_ssie_report ( void )

static

End-of-run SSIE section: per-channel enable state + TX tally.

End-of-run ssie section: per-channel enable state + tx tally; this step is contained within the board periph SSIE model and uses bounded caller or module-owned storage.

Precondition: Arguments satisfy the ranges documented for SSIE report.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board periph SSIE model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Note: The operation is synchronous and does not transfer heap ownership.

Since: 0.1.0

Definition at line 189 of file board_periph_ssie.c.

References board_console_push(), k_board_console_ch_i2s, k_ssie_console_line_cap, k_ssie_count, k_ssie_off_ssicr, priv_emu_io_errf(), RA8_INTERNAL, and s_ssie.

◆ internal_ssie_reset()

RA8_INTERNAL void internal_ssie_reset ( void )

static

Reset all SSIE channel shadows to power-on (zeroed) state.

Reset all ssie channel shadows to power-on (zeroed) state; this step is contained within the board periph SSIE model and uses bounded caller or module-owned storage.

Precondition: Arguments satisfy the ranges documented for SSIE reset.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board periph SSIE model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Note: The operation is synchronous and does not transfer heap ownership.

Since: 0.1.0

Definition at line 93 of file board_periph_ssie.c.

References k_ssie_count, k_ssie_regs, RA8_INTERNAL, and s_ssie.

◆ internal_ssie_write()

RA8_INTERNAL void internal_ssie_write	(	uc_engine *	uc,
		uint64_t	addr,
		unsigned	size,
		uint64_t	value )

static

MMIO write inside the SSIE window: route to the addressed channel.

MMIO write inside the ssie window: route to the addressed channel; this step is contained within the board periph SSIE model and uses bounded caller or module-owned storage.

Parameters

[in,out]	uc	Unicorn engine whose emulated state is read or updated.
[in]	addr	Guest address involved in the operation.
[in]	size	Size of the requested region or access in bytes.
[in]	value	Register or payload value involved in the operation.

Precondition: Arguments satisfy the ranges documented for SSIE write.; The call executes on the emulator's single owning thread.

Postcondition: State changes remain confined to the board periph SSIE model and documented output objects.; Ownership of caller-supplied storage is unchanged.

Note: The operation is synchronous and does not transfer heap ownership.

Since: 0.1.0

Definition at line 158 of file board_periph_ssie.c.

References k_ssie_base, k_ssie_count, k_ssie_off_ssiftdr, k_ssie_regs, k_ssie_stride, ssie_state_t::reg, s_ssie, and ssie_state_t::tx_samples.

Variable Documentation

◆ s_k_ssie_block

const board_periph_block_t s_k_ssie_block

static

Initial value:

                                                 = {
  .base   = (uint32_t)k_ssie_base,
  .span   = (uint32_t)k_ssie_span,
  .order  = (uint32_t)k_ssie_block_order,
  .read   = internal_ssie_read,
  .write  = internal_ssie_write,
  .tick   = nullptr,
  .reset  = internal_ssie_reset,
  .report = internal_ssie_report,
  .name   = "SSIE",
}

SSIE block descriptor (self-registered with the core).

Definition at line 215 of file board_periph_ssie.c.

Referenced by internal_ssie_block_register().

◆ s_ssie

ssie_state_t s_ssie[k_ssie_count]

static

Definition at line 83 of file board_periph_ssie.c.

Referenced by internal_ssie_read(), internal_ssie_report(), internal_ssie_reset(), and internal_ssie_write().

Data Structures

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ ssie_console_t

◆ ssie_field_t

◆ ssie_map_t

◆ ssie_off_t

◆ ssie_order_t

Function Documentation

◆ internal_ssie_block_register()

◆ internal_ssie_read()

◆ internal_ssie_report()

◆ internal_ssie_reset()

◆ internal_ssie_write()

Variable Documentation

◆ s_k_ssie_block

◆ s_ssie