Serial EEPROM API

1
Serial EEPROM API

• Supported Serial EEPROM parts
• Serial EEPROM API introduction
• Detailed Serial EEPROM API Function presentation
• Serial EEPROM example application

NETOS Software Group
2
Supported Serial EEPROM Parts

• Atmel AT25080/160/320/640 family of SPI serial
  EEPROMs.
• EEPROM sizes are 1KB, 2KB, 4KB and 8KB
  respectively.
• Driver uses four NET50 GPIO lines to interface
  with the serial EEPROM to free up a chip select
  (CS) line and the SPI interface.
• PortC, PortD, PortF, PortG and PortH GPIO lines
  are supported and I/O lines from different Ports
  can be mixed and matched.
• Driver supports the burst mode read and page mode
  write features of the serial EEPROM for optimal
  performance.

3
Supported Serial EEPROM Parts (continued)

• Driver supports the write protection features of
  the serial EEPROM.

4
Serial EEPROM API

• NASEInit()
• NASECreateSemaphores()
• NASEWrite()
• NASERead()
• NASEMemset()
• NASEBlockWriteProtect()

5
NASEInit()

• int NASEInit (unsigned long eepromType, unsigned
  long chipSelectLine, unsigned long clockLine,
  unsigned long serialIn, unsigned long
  serialOut)
• Specifies the EEPROM part and the GPIO lines used
  to interface the EEPROM. Also initializes global
  variables and the GPIO ports used to interface
  with the EEPROM part.
• Called ONCE after power up.
• eepromType can be
• AT25080, AT25160, AT25320 or AT25640

6
NASEInit() (continued)

• chipSelectLine, clockLine and serialIn can be
• PORTC_BITx, PORTD_BITx, PORTF_BITx
• serialOut can be
• PORTC_BITx, PORTD_BITx, PORTF_BITx, PORTG_BITx,
  PORTH_BITx

7
NASECreateSemaphores()

• int NASECreateSemaphores()
• Creates the semaphores used to synchronize access
  to the serial EEPROM driver API.
• Called by the user application ONCE after power
  up.
• NASEWrite(), NASERead(), NASEMemset() and
  NASEBlockWriteProtect() are semaphore protected.

8
NASEWrite()

• int NASEWrite(unsigned long offset, char
  buffer, unsigned long length)
• Writes data starting from the specified offset
  location in the serial EEPROM memory.

9
NASERead()

• int NASERead(unsigned long offset, char
  buffer, unsigned long length)
• Reads data from the serial EEPROM starting at the
  specified offset location in the serial EEPROM
  memory.

10
NASEMemset()

• int NASEMemset (unsigned long offset, char data,
  unsigned long length)
• Initializes sections of the serial EEPROM with
  the specified character.

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NASEBlockWriteProtect()

• int NASEBlockWriteProtect (unsigned char
  protectionLevel)
• Sets the write protect level for the serial
  EEPROM.
• protectionLevel can be
• WRITE_PROTECT_LEVEL0 write protection disabled
• WRITE_PROTECT_LEVEL1 write protection enabled
  for last ¼ of the address range
• WRITE_PROTECT_LEVEL2 write protection enabled
  for the second ½ of the address range
• WRITE_PROTECT_LEVEL3 write protection enabled
  for the entire address range.

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NASEBlockWriteProtect() (continued)

• Write protection settings are non-volatile.
  Thus, the write protection setting will remain
  until it is changed.

13
Serial EEPROM Example Application

• \netosx\src\examples\naseeprom
• Configured to access a AT25640 serial EEPROM
  using I/O lines from various GPIO ports.
• Verifies the functionality of the serial EEPROMs
  write protection feature.
• Allows reading / writing entire serial EEPROM
  memory 1 byte per NASERead() / NASEWrite() call
  to reading / writing 8KB with one NASERead() /
  NASEWrite() call.