ebi_sdram_example.c File Reference

AVR XMEGA External Bus Interface (EBI) example.

Copyright (c) 2010-2018 Microchip Technology Inc. and its subsidiaries.

#include <conf_board.h>
#include <stdint.h>
#include <asf.h>

Macros
#define	BOARD_EBI_SDRAM_INITDLY   (100 * 2 * sysclk_get_per2_hz() / 1000000)
	SDRAM initialization delay in number of CLKper2 cycles (100 us) More...
#define	BOARD_EBI_SDRAM_REFRESH   (16 * 2 * sysclk_get_per2_hz() / 1000000)
	SDRAM refresh interval in number of CLKper2 cycles (16 us) More...

Functions
static status_code_t	ebi_test_addr_bus (hugemem_ptr_t base, uint32_t size)
	Test the EBI address bus wired to the SDRAM. More...
static status_code_t	ebi_test_data_bus (hugemem_ptr_t base)
	Test the EBI data bus wired to the SDRAM. More...
static status_code_t	ebi_test_data_integrity (hugemem_ptr_t base, uint32_t size)
	Perform a SDRAM data integrity test. More...
int	main (void)
	Main function. More...

Variables
static struct ebi_cs_config	cs_config
	EBI chip select configuration. More...
static struct ebi_sdram_config	sdram_config
	EBI SDRAM configuration. More...

#define BOARD_EBI_SDRAM_INITDLY   (100 * 2 * sysclk_get_per2_hz() / 1000000)

SDRAM initialization delay in number of CLKper2 cycles (100 us)

Referenced by main().

#define BOARD_EBI_SDRAM_REFRESH   (16 * 2 * sysclk_get_per2_hz() / 1000000)

SDRAM refresh interval in number of CLKper2 cycles (16 us)

Referenced by main().

static status_code_t ebi_test_addr_bus ( hugemem_ptr_t  base, uint32_t  size  )

static

Test the EBI address bus wired to the SDRAM.

This function will perform an address bus test to locate any shorts or open leads to the SDRAM device.

Parameters

base	Base address of the external memory device
size	Size of the external memory device

Return values

STATUS_OK

on success, and status_code_t error code on failure

References ERR_IO_ERROR, hugemem_read8(), hugemem_write8(), and STATUS_OK.

Referenced by main().

static status_code_t ebi_test_data_bus ( hugemem_ptr_t  base )

static

Test the EBI data bus wired to the SDRAM.

This function will perform a walking 1s to locate any shorts or open leads to the SDRAM device.

Parameters

base	Base address of the external memory device

Return values

STATUS_OK

on success, and status_code_t error code on failure

References ERR_IO_ERROR, hugemem_read32(), hugemem_write32(), and STATUS_OK.

Referenced by main().

static status_code_t ebi_test_data_integrity ( hugemem_ptr_t  base, uint32_t  size  )

static

Perform a SDRAM data integrity test.

This function will perform a SDRAM data integrity test by writing 0s and 1s to the entire external device.

Parameters

base	Base address of the external memory device
size	Size of the external memory device

Return values

STATUS_OK

on success, and status_code_t error code on failure

References ERR_IO_ERROR, hugemem_read32(), hugemem_write32(), and STATUS_OK.

Referenced by main().

int main

(

void

)

Main function.

References BOARD_EBI_SDRAM_INITDLY, BOARD_EBI_SDRAM_REFRESH, board_init(), cs_config, EBI_CS_ASPACE_8MB_gc, ebi_cs_set_address_size(), ebi_cs_set_base_address(), ebi_cs_set_mode(), ebi_cs_write_config(), ebi_enable_cs(), EBI_PORT_3PORT, EBI_PORT_SDRAM, EBI_SDRAM_CS, ebi_sdram_is_ready(), ebi_sdram_set_cas_latency(), ebi_sdram_set_col_bits(), ebi_sdram_set_initialization_delay(), ebi_sdram_set_mode(), ebi_sdram_set_mode_delay(), ebi_sdram_set_refresh_period(), ebi_sdram_set_row_bits(), ebi_sdram_set_row_cycle_delay(), ebi_sdram_set_row_to_col_delay(), ebi_sdram_set_row_to_precharge_delay(), ebi_sdram_set_self_refresh_to_active_delay(), ebi_sdram_set_write_recovery_delay(), ebi_sdram_write_config(), ebi_setup_port(), ebi_test_addr_bus(), ebi_test_data_bus(), ebi_test_data_integrity(), gpio_set_pin_low, sdram_config, sleepmgr_enter_sleep(), sleepmgr_init(), and sysclk_init().

struct ebi_cs_config cs_config

static

EBI chip select configuration.

This struct holds the configuration for the chip select used to set up the SDRAM. The example code will use the EBI helper function to setup the contents before writing the configuration using ebi_cs_write_config().

Referenced by main().

struct ebi_sdram_config sdram_config

static

EBI SDRAM configuration.

This struct holds the configuration for the SDRAM. The example code will use the EBI helper function to setup the contents before writing the configuration using ebi_sdram_write_config().

Referenced by main().