External SDRAM bring-up + 64 KB write/read benchmark on EK-RA8D2. More...

#include <stdint.h>
#include "ra8_board_ek_ra8d2.h"
#include "ra8_boot_entry.h"
#include "ra8_cgc.h"
#include "ra8_err.h"
#include "ra8_isr.h"
#include "ra8_mstp.h"
#include "ra8_sdramc.h"
#include "ra8_sdramc_regs.h"
#include "ra8_time.h"

Include dependency graph for main.c:

Data Structures
struct	sdram_demo_diag_t
	First-mismatch diagnostic captured by sdram_demo_read_check. More...

Enumerations
enum	sdram_demo_const_t : uint32_t { k_sdram_demo_baud = 115200U , k_sdram_demo_period_ms = 1000U , k_sdram_demo_block_bytes = 65536U , k_sdram_demo_block_words = 16384U , k_sdram_demo_us_per_ms = 1000U }
	App-wide tunables. More...
enum	sdram_demo_byte_t : uint8_t { k_sdram_demo_ascii_zero = '0' , k_sdram_demo_ascii_a = 'a' , k_sdram_demo_dec_base = 10U , k_sdram_demo_uint_dec_max = 10U , k_sdram_demo_print_buf = 64U , k_sdram_demo_fail_buf = 96U , k_sdram_demo_hex_digits = 8U , k_sdram_demo_nyb_bits = 4U , k_sdram_demo_nyb_mask = 0x0FU }
	Single-byte ASCII conversion constants. More...
enum	sdram_demo_seed_t : uint32_t { k_sdram_demo_pattern_seed = 0xC0FFEE00UL }
	Pattern seed – recognisable hex word for SWD inspection. More...

Functions
static void	sdram_demo_panic_halt (void)
	Park forever after a fatal init failure.
static void	sdram_demo_setup_or_halt (void)
	Bring CGC + SysTick + console + SDRAM up.
static uint32_t	sdram_demo_mbps (uint32_t bytes, uint32_t ms)
	Compute throughput in MB/s given a byte count and millisecond span.
static uint32_t	sdram_demo_write_pass (uint32_t base)
	Write base + i into every word of the SDRAM block.
static bool	sdram_demo_read_check (uint32_t base, uint32_t elapsed, sdram_demo_diag_t diag)
	Read every word back and check it matches base + i.
static uint8_t	sdram_demo_uint_to_hex (uint8_t *buf, uint32_t v)
	Render `v` as exactly 8 lowercase hex digits into `buf`.
static uint8_t	sdram_demo_uint_to_dec (uint8_t *buf, uint32_t v)
	Write a decimal uint32 into buf; returns bytes written.
static uint32_t	sdram_demo_format_line (uint8_t *out, uint32_t w_mbps, uint32_t r_mbps)
	Format the per-cycle MB/s line into `out`, return its length.
static uint32_t	sdram_demo_format_fail (uint8_t out, const sdram_demo_diag_t diag)
	Format the read-back FAIL diagnostic line into `out`.
void	main (void)
	Application entry.

Variables
static const uint8_t	k_sdram_demo_pass_msg [] = "sdram: bench OK\r\n"
	Verdict line emitted only when a read-back pass matched every word (never on a "sdram: FAIL idx=" path); the HIL scrape keys on this success-only string.

Detailed Description

External SDRAM bring-up + 64 KB write/read benchmark on EK-RA8D2.

Tag: [Ring 6 / APP] {World: S}

Standalone EVM-tier app that exercises the external SDRAM controller driver (libs/ra8_hal/inc/ra8_sdramc.h). The EK-RA8D2 carries a 64 MB ISSI IS42S32160F SDRAM (16M x 32) wired to the BUS pins with the controller-mapped window starting at k_ra8_sdram_base_addr (0x68000000). The flow:

ra8_cgc_init – clocks up.
ra8_mstp_init + console pins (PD02 / PD03 SCI8).
ra8_sdramc_init – runs the documented SDRAM bring-up sequence (PALL -> MRS -> AREF enable).
Write a 64 KB block of incrementing 32-bit words into the SDRAM window starting at k_ra8_sdram_base_addr. Time the write and read phases via ra8_time_ms and emit "sdram: w=NN MB/s r=NN MB/s\r\n" over SCI8 once a second. On a clean read-back it also emits the success-only verdict line "sdram: bench OK\r\n" that the HIL scrape keys on (never printed on a "sdram: FAIL idx=" path). LED1 toggles per cycle; LED2 latches on read-back mismatch.

Bare EK-RA8D2 only – the SDRAM is on-board.

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

Since: 0.1.0

Definition in file main.c.

Enumeration Type Documentation

◆ sdram_demo_byte_t

enum sdram_demo_byte_t : uint8_t

Single-byte ASCII conversion constants.

Enumerator
k_sdram_demo_ascii_zero	SDRAM demo ascii zero.
k_sdram_demo_ascii_a	SDRAM demo ascii a.
k_sdram_demo_dec_base	SDRAM demo dec base.
k_sdram_demo_uint_dec_max	Max digits in a uint32 base-10.
k_sdram_demo_print_buf	Max bytes in one throughput line.
k_sdram_demo_fail_buf	Max bytes in the FAIL diag line.
k_sdram_demo_hex_digits	Hex digits in a uint32.
k_sdram_demo_nyb_bits	Bits per hex nibble.
k_sdram_demo_nyb_mask	Mask for one nibble.

Definition at line 57 of file main.c.

◆ sdram_demo_const_t

enum sdram_demo_const_t : uint32_t

App-wide tunables.

Enumerator
k_sdram_demo_baud	SDRAM demo baud.
k_sdram_demo_period_ms	SDRAM demo period ms.
k_sdram_demo_block_bytes	64 KB window per pass.
k_sdram_demo_block_words	65536 / sizeof(uint32_t).
k_sdram_demo_us_per_ms	Conversion factor used in mbps.

Definition at line 48 of file main.c.

◆ sdram_demo_seed_t

enum sdram_demo_seed_t : uint32_t

Pattern seed – recognisable hex word for SWD inspection.

Enumerator
k_sdram_demo_pattern_seed	SDRAM demo pattern seed.

Definition at line 85 of file main.c.

Function Documentation

◆ main()

void main ( void )

Application entry.

The application entry point Reset_Handler hands control to.

Bench-tests SDRAM and prints MB/s.

Precondition: Reset_Handler has copied .data and zeroed .bss.; SystemInit has set VTOR, FPU, and priority grouping.

Postcondition: On clean entry the CPU stays in the bench + blink loop.; On read-back mismatch LED2 latches ON.

Since: 0.1.0

Definition at line 365 of file main.c.

References k_ra8_board_led1, k_ra8_board_led2, k_ra8_ok, k_sdram_demo_block_bytes, k_sdram_demo_fail_buf, k_sdram_demo_pass_msg, k_sdram_demo_pattern_seed, k_sdram_demo_period_ms, k_sdram_demo_print_buf, ra8_board_led_on(), ra8_board_led_toggle(), ra8_board_uart_console_write(), ra8_delay_ms(), ra8_isr_globals_enable(), sdram_demo_format_fail(), sdram_demo_format_line(), sdram_demo_mbps(), sdram_demo_panic_halt(), sdram_demo_read_check(), sdram_demo_setup_or_halt(), and sdram_demo_write_pass().

◆ sdram_demo_format_fail()

uint32_t sdram_demo_format_fail	(	uint8_t *	out,
		const sdram_demo_diag_t *	diag )

static

Format the read-back FAIL diagnostic line into out.

Emits sdram: FAIL idx=<dec> exp=<hex> got=<hex> n=<dec> so a HIL log shows the corruption signature. The literal sdram: FAIL prefix is what the HIL negative-match regex keys on.

Parameters

[out]	out	Destination buffer (>= k_sdram_demo_fail_buf bytes).
[in]	diag	First-mismatch diagnostic from sdram_demo_read_check.

Returns: Number of bytes written (no NUL terminator).

Precondition: out is non-NULL with >= k_sdram_demo_fail_buf capacity.; diag->count is non-zero (a mismatch was found).

Postcondition: No bytes beyond the returned length are touched.

Since: 0.1.0

Definition at line 324 of file main.c.

References sdram_demo_diag_t::count, sdram_demo_diag_t::expected, sdram_demo_diag_t::first_idx, sdram_demo_diag_t::got, sdram_demo_uint_to_dec(), and sdram_demo_uint_to_hex().

Referenced by main().

◆ sdram_demo_format_line()

uint32_t sdram_demo_format_line	(	uint8_t *	out,
		uint32_t	w_mbps,
		uint32_t	r_mbps )

static

Format the per-cycle MB/s line into out, return its length.

Parameters

[out]	out	Destination buffer (>= k_sdram_demo_print_buf bytes).
[in]	w_mbps	Write throughput in MB/s.
[in]	r_mbps	Read throughput in MB/s.

Returns: Number of bytes written (no NUL terminator).

Precondition: out is non-NULL with >= k_sdram_demo_print_buf capacity.

Postcondition: No bytes beyond the returned length are touched.

Since: 0.1.0

Definition at line 288 of file main.c.

References sdram_demo_uint_to_dec().

Referenced by main().

◆ sdram_demo_mbps()

uint32_t sdram_demo_mbps	(	uint32_t	bytes,
		uint32_t	ms )

static

Compute throughput in MB/s given a byte count and millisecond span.

Returns (bytes / 1e6) / (ms / 1000) = bytes / (ms * 1000). The function clamps ms to 1 to avoid divide-by-zero when the benchmark loop is too fast to register on the millisecond tick.

Parameters

[in]	bytes	Total bytes transferred.
[in]	ms	Elapsed time in milliseconds.

Returns: MB/s as an integer (truncated).

Precondition: None.

Postcondition: Return value never overflows uint32 for bytes <= 4 GB and ms >= 1.

Since: 0.1.0

Definition at line 159 of file main.c.

References k_sdram_demo_us_per_ms.

Referenced by main().

◆ sdram_demo_panic_halt()

void sdram_demo_panic_halt ( void )

static

Park forever after a fatal init failure.

Precondition: Called only after a fatal error in boot.

Postcondition: CPU is parked; only a debugger or external reset wakes it.

Since: 0.1.0

Definition at line 100 of file main.c.

Referenced by main(), and sdram_demo_setup_or_halt().

◆ sdram_demo_read_check()

bool sdram_demo_read_check	(	uint32_t	base,
		uint32_t *	elapsed,
		sdram_demo_diag_t *	diag )

static

Read every word back and check it matches base + i.

Parameters

[in]	base	Seed used by the matching write pass.
[out]	elapsed	Receives the elapsed milliseconds.
[out]	diag	Receives the first-mismatch diagnostic.

Returns: true if every word matches the expected pattern.

Precondition: elapsed and diag are non-NULL.

Postcondition: On success *elapsed holds the read-pass duration.; diag->count holds the total mismatch count.

Since: 0.1.0

Definition at line 198 of file main.c.

References sdram_demo_diag_t::count, sdram_demo_diag_t::expected, sdram_demo_diag_t::first_idx, sdram_demo_diag_t::got, k_ra8_sdram_base_addr, k_sdram_demo_block_words, and ra8_time_ms().

Referenced by main().

◆ sdram_demo_setup_or_halt()

void sdram_demo_setup_or_halt ( void )

static

Bring CGC + SysTick + console + SDRAM up.

Panic-halts on fail.

Since: 0.1.0

Definition at line 112 of file main.c.

References k_ra8_board_led1, k_ra8_board_led2, k_ra8_clock_id_cpuclk0, k_ra8_ok, k_sdram_demo_baud, ra8_board_led_init(), ra8_board_uart_console_init(), ra8_cgc_get_clock_hz(), ra8_cgc_init(), ra8_mstp_init(), ra8_sdramc_init(), ra8_time_init(), and sdram_demo_panic_halt().

Referenced by main().

◆ sdram_demo_uint_to_dec()

uint8_t sdram_demo_uint_to_dec	(	uint8_t *	buf,
		uint32_t	v )

static

Write a decimal uint32 into buf; returns bytes written.

Parameters

[out]	buf	Destination buffer (must hold at least 10 chars).
[in]	v	Value to render.

Returns: Number of ASCII digits written.

Precondition: buf is non-NULL with >= 10 bytes capacity.

Postcondition: No null terminator is written.

Since: 0.1.0

Definition at line 254 of file main.c.

References k_sdram_demo_ascii_zero, k_sdram_demo_dec_base, and k_sdram_demo_uint_dec_max.

Referenced by sdram_demo_format_fail(), and sdram_demo_format_line().

◆ sdram_demo_uint_to_hex()

uint8_t sdram_demo_uint_to_hex	(	uint8_t *	buf,
		uint32_t	v )

static

Render v as exactly 8 lowercase hex digits into buf.

Parameters

[out]	buf	Destination (must hold >= k_sdram_demo_hex_digits).
[in]	v	Value to render.

Returns: Number of digits written (always k_sdram_demo_hex_digits).

Precondition: buf is non-NULL with >= 8 bytes capacity.

Postcondition: No null terminator is written.

Since: 0.1.0

Definition at line 229 of file main.c.

References k_sdram_demo_ascii_a, k_sdram_demo_ascii_zero, k_sdram_demo_dec_base, k_sdram_demo_hex_digits, k_sdram_demo_nyb_bits, and k_sdram_demo_nyb_mask.

Referenced by sdram_demo_format_fail().

◆ sdram_demo_write_pass()

uint32_t sdram_demo_write_pass ( uint32_t base )

static

Write base + i into every word of the SDRAM block.

Parameters

[in] base Seed value mixed into the pattern.

Returns: Elapsed milliseconds.

Precondition: ra8_sdramc_init succeeded so the SDRAM window is live.

Postcondition: Every word in the 64 KB block holds base + i.

Since: 0.1.0

Definition at line 175 of file main.c.

References k_ra8_sdram_base_addr, k_sdram_demo_block_words, and ra8_time_ms().

Referenced by main().

Variable Documentation

◆ k_sdram_demo_pass_msg

const uint8_t k_sdram_demo_pass_msg[] = "sdram: bench OK\r\n"

static

Verdict line emitted only when a read-back pass matched every word (never on a "sdram: FAIL idx=" path); the HIL scrape keys on this success-only string.

Definition at line 92 of file main.c.

Referenced by main().

Data Structures

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ sdram_demo_byte_t

◆ sdram_demo_const_t

◆ sdram_demo_seed_t

Function Documentation

◆ main()

◆ sdram_demo_format_fail()

◆ sdram_demo_format_line()

◆ sdram_demo_mbps()

◆ sdram_demo_panic_halt()

◆ sdram_demo_read_check()

◆ sdram_demo_setup_or_halt()

◆ sdram_demo_uint_to_dec()

◆ sdram_demo_uint_to_hex()

◆ sdram_demo_write_pass()

Variable Documentation

◆ k_sdram_demo_pass_msg