1# ScsiPeripheral_DeviceMemMap 2 3 4## Overview 5 6Represents the device memory mapping created by calling **OH_ScsiPeripheral_CreateDeviceMemMap**. The buffer that uses the device memory mapping can provide better performance. 7 8**Since**: 18 9 10**Related module**: [SCSI Peripheral DDK](_s_c_s_i.md) 11 12 13## Summary 14 15 16### Member Variables 17 18| Name| Description| 19| -------- | -------- | 20| uint8_t \*const [address](#address) | Buffer address.| 21| const size_t [size](#size) | Buffer size.| 22| uint32_t [offset](#offset) | Offset of the used buffer. The default value is **0**, indicating that there is no offset and the buffer starts from the specified address.| 23| uint32_t [bufferLength](#bufferlength) | Length of the used buffer. By default, the value is equal to the size of the buffer, indicating that the entire buffer is used.| 24| uint32_t [transferredLength](#transferredlength) | Length of the data to be transferred.| 25 26 27## Member Variable Description 28 29 30### address 31 32``` 33uint8_t* const ScsiPeripheral_DeviceMemMap::address 34``` 35 36**Description** 37 38Buffer address. 39 40 41### bufferLength 42 43``` 44uint32_t ScsiPeripheral_DeviceMemMap::bufferLength 45``` 46 47**Description** 48 49Length of the used buffer. By default, the value is equal to the size of the buffer, indicating that the entire buffer is used. 50 51 52### offset 53 54``` 55uint32_t ScsiPeripheral_DeviceMemMap::offset 56``` 57 58**Description** 59 60Offset of the used buffer. The default value is **0**, indicating that there is no offset and the buffer starts from the specified address. 61 62 63### size 64 65``` 66const size_t ScsiPeripheral_DeviceMemMap::size 67``` 68 69**Description** 70 71Buffer size. 72 73 74### transferredLength 75 76``` 77uint32_t ScsiPeripheral_DeviceMemMap::transferredLength 78``` 79 80**Description** 81 82Length of the data to be transferred. 83