This library aims to support the following MRAM memory chips from Everspin Technologies for Arduino core:

See examples/ folder.

Available classes are:

• MR25H128
• MR25H256
• MR25H10
• MR25H40

The first two chips only need two bytes (uint16_t) to address all the memory on the chip. The last two require three bytes (uint32_t). The following documentation uses addr_t to describe the addressing datatype.

The MR25HXXX family supports four different memory protection modes:

Each class provides the following methods. Look into source code for more documentation.

Get total number of bytes in memory:

• addr_t memorySize()

(Un-)Initialize the mram chip object:

• void begin()
• void end()

Methods for direct status register manipulation (not recommended to do manually):

• StatusRegister readStatusRegister()
• void writeStatusRegister(StatusRegister sr)
• void enableWriteStatusRegister()
• void disableWriteStatusRegister()
• bool isStatusRegisterWritable(StatusRegister sr)
• bool isStatusRegisterWritable()
• bool isWriteEnabled()

Get/set memory protection mode:

• ProtectionMode getProtectionMode(StatusRegister sr)
• ProtectionMode getProtectionMode()
• void setProtectionMode(ProtectionMode pmode)

Read/write methods:

• void enableWrite(): does not need to be called explicitly before write operation, but saves a few cpu cycles
• void disableWrite()
• bool readBytes(uint8_t *dst, addr_t address, addr_t n)
• bool writeBytes(addr_t address, uint8_t *src, addr_t n)

Power saving:

• void sleep()
• void wake()
• bool isSleeping(): every command sent while sleeping will be ignored

Helper functions:

• void eraseChip(uint8_t value = 0xff)
• void eraseFullChip(uint8_t value = 0xff)