Media Support Routines

Media support routines provide media management functions. More...

Functions
int32_t	fs_mc_read_cd (uint32_t drive_num)
	Callback function used to read Card Detect (CD) pin state when Memory Card is used in SPI mode.
int32_t	fs_mc_read_wp (uint32_t drive_num)
	Callback function used to read Write Protect (WP) pin state when Memory Card is used in SPI mode.
int32_t	fs_mc_spi_control_ss (uint32_t drive_num, uint32_t ss)
	Callback function used to control Slave Select signal when Memory Card is used in SPI mode.
fsLockUnlock *	fs_mc_lock_unlock (uint32_t drive_num)
	Callback function used to retrieve password management information in order to manage locked memory card device during initialization.

Description

Function Documentation

fsLockUnlock * fs_mc_lock_unlock

(

uint32_t

drive_num

)

Parameters

[in]

drive_num

Memory Card Drive number

Returns

pointer to fsLockUnlock structure or NULL when structure not available

The function fs_mc_lock_unlock returns media lock/unlock information structure. Application optionally implements this function and ensure proper drive_num mapping.

The argument drive_num is specifying a Memory Card drive instance number.

Code Example

// Memory card password
const uint8_t mc0_pass[] = { 0x01, 0x02, 0x03, 0x04, 0x05 };
 
// Media lock/unlock information structure
fsLockUnlock  mc0_lock;
 
// Provide password management information
fsLockUnlock *fs_mc_lock_unlock (uint32_t drive_num) {
 
  if (drive_num == 0) {
    // Drive M0 is requesting password protection info
    mc0_lock.password = mc0_pass;
    mc0_lock.length   = 5;
    mc0_lock.flags    = 0; // Unlock memory card
 
    return (&mc0_lock);
  }
  return (NULL);
}

int32_t fs_mc_read_cd

(

uint32_t

drive_num

)

Parameters

[in]

drive_num

Memory Card Drive number

Returns

1:card detected, 0:card not detected, or error

The function fs_mc_read_cd returns memory card detection state. Application optionally implements this function and ensure proper drive_num mapping to Card Detect (CD) pin on the Memory Card socket.

The argument drive_num is specifying a Memory Card drive instance number.

Code Example

int32_t fs_mc_read_cd (uint32_t drive_num) {
  
  switch (drive_num) {
    case 0:
      printf ("Drive M0 requests Memory Card detection state!\n");
      if (GPIO->PINSTATE & MC0_CARD_DETECT_PIN) {
        // Memory Card is detected
        return 1;
      }
      break;

    case 1:
      printf ("Drive M1 requests Memory Card detection state!\n");
      if (GPIO->PINSTATE & MC1_CARD_DETECT_PIN) {
        // Memory Card is detected
        return 1;
      }
      break;
    default:
      break;
  }
  // Card not detected or error
  return (0);
}

int32_t fs_mc_read_wp

(

uint32_t

drive_num

)

Parameters

[in]

drive_num

Memory Card Drive number

Returns

1:write protected, 0:not write protected, or error

The function fs_mc_read_wp returns memory card write protection state. Application optionally implements this function and ensure proper drive_num mapping to Write Protect (WP) pin on the Memory Card socket.

The argument drive_num is specifying a Memory Card drive instance number.

int32_t fs_mc_spi_control_ss	(	uint32_t	drive_num,
		uint32_t	ss
	)

Parameters

[in]	drive_num	Memory Card Drive number
[in]	ss	Slave select signal state

Returns

execution status

• slave select signal state: 1:active, 0:inactive
• -1: slave select signal control is not implemented

The function fs_mc_spi_control_ss controls Slave Select (SS) signal state. Application optionally implements this function and ensure proper drive_num mapping to SS pin on the Memory Card socket. Its return value indicates current SS signal state or when -1 is returned, that SS signal control is not implemented by this function and must be controlled using SPI driver.

The argument drive_num is specifying a Memory Card drive instance number.

The argument ss is specifying a Slave Select signal state: 0=inactive, 1=active