See Quick Start Guide for the XMEGA EBI Driver .

This is a driver for configuring, enabling, disabling and use of the on-chip external bus interface (EBI).

Dependencies

The external bus interface depends on the following modules:

System Clock Management for peripheral clock control and getting bus speeds.
Sleep manager for setting available sleep mode.

Quick Start Guide

See Quick Start Guide for the XMEGA EBI Driver

Modules
	Related Project(s)
	In this section you can find all the projects related to the External Bus Interface (EBI).

	Quick Start Guide(s)
	In this section you can find a list of all Quick Start guides related to the External Bus Interface (EBI).

	EBI port/pin configuration
	This is a driver for configuring the external bus interface port.

	Common EBI test functions
	This module contains common functions for testing of External Bus Interface (EBI) and the setup of external RAM devices.

Data Structures
struct	ebi_cs_config
	External bus interface chip select configuration. More...

struct	ebi_sdram_config
	External bus interface SDRAM configuration. More...

Macros
#define	EBI_SDRAM_CS 3
	Chip select on the EBI that can be configured for SDRAM operation. More...

External Bus Interface management
void	ebi_cs_write_config (const uint8_t cs, const struct ebi_cs_config *config)
	Write EBI chip select configuration to hardware. More...

void	ebi_cs_read_config (const uint8_t cs, struct ebi_cs_config *config)
	Read EBI chip select configuration from hardware. More...

void	ebi_sdram_write_config (const struct ebi_sdram_config *config)
	Write EBI SDRAM configuration to hardware. More...

void	ebi_sdram_read_config (struct ebi_sdram_config *config)
	Read EBI SDRAM configuration from hardware. More...

void	ebi_enable_cs (const uint8_t cs, const struct ebi_cs_config *config)
	Enable an EBI chip select. More...

void	ebi_disable_cs (const uint8_t cs)
	Disable an EBI chip select. More...

static bool	ebi_sdram_is_ready (void)
	Check if SDRAM is ready for access. More...

External Bus Interface Chip Select configuration helper functions
static void	ebi_cs_set_mode (struct ebi_cs_config *config, EBI_CS_MODE_t mode)
	Set chip select mode. More...

static void	ebi_cs_set_address_size (struct ebi_cs_config *config, EBI_CS_ASPACE_t size)
	Set chip select address size. More...

static void	ebi_cs_set_sram_wait_states (struct ebi_cs_config *config, EBI_CS_SRWS_t cycles)
	Set chip select SRAM wait states. More...

static void	ebi_cs_set_base_address (struct ebi_cs_config *config, uint32_t address)
	Set chip select base address. More...

External Bus Interface SDRAM configuration helper functions
static void	ebi_sdram_set_mode (struct ebi_cs_config *config, EBI_CS_SDMODE_t mode)
	Set SDRAM mode. More...

static void	ebi_sdram_set_cas_latency (struct ebi_sdram_config *config, const uint8_t cas)
	Set SDRAM CAS latency. More...

static void	ebi_sdram_set_row_bits (struct ebi_sdram_config *config, const uint8_t bits)
	Set number of SDRAM row bits. More...

static void	ebi_sdram_set_col_bits (struct ebi_sdram_config *config, const uint8_t bits)
	Set number of SDRAM column bits. More...

static void	ebi_sdram_set_refresh_period (struct ebi_sdram_config *config, const uint16_t period)
	Set SDRAM refresh period. More...

static void	ebi_sdram_set_initialization_delay (struct ebi_sdram_config *config, const uint16_t delay)
	Set SDRAM initialization delay. More...

static void	ebi_sdram_set_mode_delay (struct ebi_sdram_config *config, const EBI_MRDLY_t delay)
	Set SDRAM mode delay. More...

static void	ebi_sdram_set_row_cycle_delay (struct ebi_sdram_config *config, const EBI_ROWCYCDLY_t delay)
	Set SDRAM row cycle delay. More...

static void	ebi_sdram_set_row_to_precharge_delay (struct ebi_sdram_config *config, const EBI_RPDLY_t delay)
	Set SDRAM row to pre-charge delay. More...

static void	ebi_sdram_set_write_recovery_delay (struct ebi_sdram_config *config, const EBI_WRDLY_t delay)
	Set SDRAM write recovery delay. More...

static void	ebi_sdram_set_self_refresh_to_active_delay (struct ebi_sdram_config *config, const EBI_ESRDLY_t delay)
	Set SDRAM exit self refresh to active delay. More...

static void	ebi_sdram_set_row_to_col_delay (struct ebi_sdram_config *config, const EBI_ROWCOLDLY_t delay)
	Set SDRAM row to column delay. More...

External Bus Interface SDRAM power management
static void	ebi_sdram_enable_self_refresh (void)
	Enable SDRAM self refresh mode. More...

static void	ebi_sdram_disable_self_refresh (void)
	Disable SDRAM self refresh mode. More...

#define EBI_SDRAM_CS 3

Chip select on the EBI that can be configured for SDRAM operation.

Referenced by main(), and memories_initialization().

void ebi_cs_read_config	(	const uint8_t	cs,
		struct ebi_cs_config *	config
	)

Read EBI chip select configuration from hardware.

This function will read the EBI chip select hardware configuration and put it into the ebi_cs_config argument.

Parameters

cs	Chip select number to read configuration from
config	Pointer to an ebi_cs_config variable

References ebi_cs_config::base_address, cpu_irq_restore(), cpu_irq_save(), ebi_cs_config::ctrla, ebi_cs_config::ctrlb, ebi_get_cs_addr_from_cs_num(), sysclk_disable_module(), SYSCLK_EBI, sysclk_enable_module(), sysclk_module_is_enabled(), and SYSCLK_PORT_GEN.

static void ebi_cs_set_address_size	(	struct ebi_cs_config *	config,
		EBI_CS_ASPACE_t	size
	)

inlinestatic

Set chip select address size.

This function helps the caller setting the chip select address size. The different sizes are provided by an EBI_CS_ASPACE_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_cs_config variable
size	Chip select address size given by an EBI_CS_ASPACE_t type

References ebi_cs_config::ctrla, and EBI_CS_ASPACE_gm.

Referenced by main(), and memories_initialization().

static void ebi_cs_set_base_address	(	struct ebi_cs_config *	config,
		uint32_t	address
	)

inlinestatic

Set chip select base address.

This function helps the caller setting the chip select base address, e.g., the lowest address space enabled by the chip select.

Parameters

config	Pointer to an ebi_cs_config variable
address	The chip select base address

References ebi_cs_config::base_address.

Referenced by main(), and memories_initialization().

static void ebi_cs_set_mode	(	struct ebi_cs_config *	config,
		EBI_CS_MODE_t	mode
	)

inlinestatic

Set chip select mode.

This function helps the caller setting the chip select mode. The different modes are provided by an EBI_CS_MODE_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_cs_config variable
mode	Chip select mode given by an EBI_CS_MODE_t type

References ebi_cs_config::ctrla.

Referenced by main(), and memories_initialization().

static void ebi_cs_set_sram_wait_states	(	struct ebi_cs_config *	config,
		EBI_CS_SRWS_t	cycles
	)

inlinestatic

Set chip select SRAM wait states.

This function helps the caller setting the chip select SRAM wait states. The different SRAM wait states (cycles) are provided by an EBI_CS_SRWS_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_cs_config variable
cycles	Chip select SRAM wait states given by an EBI_CS_SRWS_t type

References ebi_cs_config::ctrlb.

Referenced by main().

void ebi_cs_write_config	(	const uint8_t	cs,
		const struct ebi_cs_config *	config
	)

Write EBI chip select configuration to hardware.

This function will write an ebi_cs_config struct to the selected chip select hardware.

Parameters

cs	Chip select number to write configuration for
config	Pointer to an ebi_cs_config variable

References ebi_cs_config::base_address, cpu_irq_restore(), cpu_irq_save(), ebi_cs_config::ctrla, ebi_cs_config::ctrlb, ebi_get_cs_addr_from_cs_num(), sysclk_disable_module(), SYSCLK_EBI, sysclk_enable_module(), sysclk_module_is_enabled(), and SYSCLK_PORT_GEN.

Referenced by main(), and memories_initialization().

void ebi_disable_cs ( const uint8_t cs )

Disable an EBI chip select.

Parameters

cs	Chip select number to disable

References cpu_irq_restore(), cpu_irq_save(), ebi_enabled_chip_selects, ebi_get_cs_addr_from_cs_num(), SLEEPMGR_IDLE, sleepmgr_unlock_mode(), sysclk_disable_module(), SYSCLK_EBI, and SYSCLK_PORT_GEN.

void ebi_enable_cs	(	const uint8_t	cs,
		const struct ebi_cs_config *	config
	)

Enable an EBI chip select.

Parameters

cs	Chip select number to enable
config	Pointer to an ebi_cs_config variable

References cpu_irq_restore(), cpu_irq_save(), ebi_cs_config::ctrla, ebi_enabled_chip_selects, ebi_get_cs_addr_from_cs_num(), SLEEPMGR_IDLE, sleepmgr_lock_mode(), SYSCLK_EBI, sysclk_enable_module(), and SYSCLK_PORT_GEN.

Referenced by main(), and memories_initialization().

static void ebi_sdram_disable_self_refresh ( void )

inlinestatic

Disable SDRAM self refresh mode.

This function makes the EBI hardware send a command to the SDRAM to leave self refresh mode.

References cpu_irq_restore(), cpu_irq_save(), SLEEPMGR_IDLE, and sleepmgr_lock_mode().

static void ebi_sdram_enable_self_refresh ( void )

inlinestatic

Enable SDRAM self refresh mode.

This function makes the EBI hardware send a command to the SDRAM to enter self refresh mode.

References cpu_irq_restore(), cpu_irq_save(), SLEEPMGR_IDLE, and sleepmgr_unlock_mode().

static bool ebi_sdram_is_ready ( void )

inlinestatic

Check if SDRAM is ready for access.

This function must be checked after the SDRAM chip select has been enabled. It will return true when the SDRAM is initialized.

Return values

true	when SDRAM is ready, false otherwise

Referenced by main(), and memories_initialization().

void ebi_sdram_read_config ( struct ebi_sdram_config * config )

Read EBI SDRAM configuration from hardware.

This function will read the SDRAM EBI hardware configuration and put it into the ebi_cs_config argument.

Note: SDRAM is by design limited to chip select 3.

Parameters

config Pointer to an ebi_sdram_config variable

References cpu_irq_restore(), cpu_irq_save(), ebi_sdram_config::init_delay, ebi_sdram_config::refresh_period, ebi_sdram_config::sdramctrla, ebi_sdram_config::sdramctrlb, ebi_sdram_config::sdramctrlc, sysclk_disable_module(), SYSCLK_EBI, sysclk_enable_module(), sysclk_module_is_enabled(), and SYSCLK_PORT_GEN.

static void ebi_sdram_set_cas_latency	(	struct ebi_sdram_config *	config,
		const uint8_t	cas
	)

inlinestatic

Set SDRAM CAS latency.

This function helps the caller setting the SDRAM CAS latency.

Parameters

config	Pointer to an ebi_sdram_config variable
cas	SDRAM CAS latency, 2 or 3

References Assert, and ebi_sdram_config::sdramctrla.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_col_bits	(	struct ebi_sdram_config *	config,
		const uint8_t	bits
	)

inlinestatic

Set number of SDRAM column bits.

This function helps the caller setting the number of SDRAM column bits.

Parameters

config	Pointer to an ebi_sdram_config variable
bits	Number of column bits, 8 to 11

References Assert, and ebi_sdram_config::sdramctrla.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_initialization_delay	(	struct ebi_sdram_config *	config,
		const uint16_t	delay
	)

inlinestatic

Set SDRAM initialization delay.

This function helps the caller setting the SDRAM initialization delay as a number of peripheral 2x clock cycles (CLKper2).

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDREAM initialization delay, number of CLKper2 cycles

References ebi_sdram_config::init_delay.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_mode	(	struct ebi_cs_config *	config,
		EBI_CS_SDMODE_t	mode
	)

inlinestatic

Set SDRAM mode.

This function helps the caller setting the SDRAM mode. The different modes are provided by an EBI_CS_SDMODE_t type from the toolchain header files.

Note: This function needs a pointer to an ebi_cs_config struct, not an ebi_sdram_config struct as the other SDRAM configuration helper function does.

Parameters

config	Pointer to an ebi_cs_config variable
mode	SDRAM mode given by an EBI_CS_SDMODE_t type

References ebi_cs_config::ctrlb.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_mode_delay	(	struct ebi_sdram_config *	config,
		const EBI_MRDLY_t	delay
	)

inlinestatic

Set SDRAM mode delay.

This function helps the caller setting the SDRAM mode delay as a number of peripheral 2x clock cycles (CLKper2). The different modes are provided by an EBI_MRDLY_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDRAM mode delay given by an EBI_MRDLY_t type

References ebi_sdram_config::sdramctrlb.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_refresh_period	(	struct ebi_sdram_config *	config,
		const uint16_t	period
	)

inlinestatic

Set SDRAM refresh period.

This function helps the caller setting the SDRAM refresh period as a number of peripheral 2x clock cycles (CLKper2).

Parameters

config	Pointer to an ebi_sdram_config variable
period	SDREAM refresh period, number of CLKper2 cycles

References ebi_sdram_config::refresh_period.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_row_bits	(	struct ebi_sdram_config *	config,
		const uint8_t	bits
	)

inlinestatic

Set number of SDRAM row bits.

This function helps the caller setting the number of SDRAM row bits.

Parameters

config	Pointer to an ebi_sdram_config variable
bits	Number of row bits, 11 or 12

References Assert, and ebi_sdram_config::sdramctrla.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_row_cycle_delay	(	struct ebi_sdram_config *	config,
		const EBI_ROWCYCDLY_t	delay
	)

inlinestatic

Set SDRAM row cycle delay.

This function helps the caller setting the SDRAM row cycle delay as a number of peripheral clock 2x cycles (CLKper2). The different delays are provided by an EBI_ROWCYCDLY_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDRAM row cycle delay given by an EBI_ROWCYCDLY_t type

References ebi_sdram_config::sdramctrlb.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_row_to_col_delay	(	struct ebi_sdram_config *	config,
		const EBI_ROWCOLDLY_t	delay
	)

inlinestatic

Set SDRAM row to column delay.

This function helps the caller setting the SDRAM row to column delay as a number of peripheral clock 2x cycles (CLKper2). The different delays are provided by an EBI_ROWCOLDLY_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDRAM row to column delay given by an EBI_ROWCOLDLY_t type

References ebi_sdram_config::sdramctrlc.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_row_to_precharge_delay	(	struct ebi_sdram_config *	config,
		const EBI_RPDLY_t	delay
	)

inlinestatic

Set SDRAM row to pre-charge delay.

This function helps the caller setting the SDRAM row to pre-charge delay as a number of peripheral clock 2x cycles (CLKper2). The different delays are provided by an EBI_RPDLY_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDRAM row to pre-charge delay given by an EBI_ROWCYCDLY_t type

References ebi_sdram_config::sdramctrlb.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_self_refresh_to_active_delay	(	struct ebi_sdram_config *	config,
		const EBI_ESRDLY_t	delay
	)

inlinestatic

Set SDRAM exit self refresh to active delay.

This function helps the caller setting the SDRAM exit self refresh to active delay as a number of peripheral clock 2x cycles (CLKper2). The different delays are provided by an EBI_ESRDLY_t type from the toolchain header files.

Parameters

config	Pointer to an ebi_sdram_config variable
delay	SDRAM exit self refresh to active delay given by an EBI_ESRDLY_t type

References ebi_sdram_config::sdramctrlc.

Referenced by main(), and memories_initialization().

static void ebi_sdram_set_write_recovery_delay	(	struct ebi_sdram_config *	config,
		const EBI_WRDLY_t	delay
	)

inlinestatic

Set SDRAM write recovery delay.

This function helps the caller setting the SDRAM write recovery delay as a number of peripheral clock 2x cycles (CLKper2). The different delays are provided by an EBI_WRDLY_t type from the toolchain header files.

Parameters