ReadSpmBuffer

Applicability

Product	Supported
Atlas 350 Accelerator Card	√
Atlas A3 training product/Atlas A3 inference product	√
Atlas A2 training product/Atlas A2 inference product	√
Atlas 200I/500 A2 inference product	x
Atlas inference product AI Core	√
Atlas inference product Vector Core	x
Atlas training product	√

Function Usage

Reads data from the SPM buffer back to the local data.

Prototype

Applicable to continuous and discontinuous data readback:

template <typename T>
__aicore__ inline void ReadSpmBuffer(const LocalTensor<T>& readBuffer, const DataCopyParams& copyParams, int32_t readOffset = 0)

Applicable to continuous temporary data readback:

template <typename T>
__aicore__ inline void ReadSpmBuffer(const LocalTensor<T>& readBuffer, const int32_t readSize, int32_t readOffset = 0)

Parameters

**Table 1** API parameters
Parameter	Input/Output	Meaning
readBuffer	Input	Readback target local memory.
copyParams	Input	Movement parameter, DataCopyParams type. For details about the structure definition of DataCopyParams, see Table 2.
readSize	Input	Number of read elements.
readOffset	Input	Offset of the SPM buffer, in bytes.

**Table 2** Parameters in the **DataCopyParams** structure
Parameter	Description
blockCount	Number of data chunks to be transferred, which is of the uint16_t type. The value range is [1, 4095].
blockLen	Length of each data chunk to be transferred, in the unit of a data block (32 bytes). The value is of the uint16_t type. The value range is [1, 65535]. Notes: When dst is located in C2PIPE2GM, the unit is 128 bytes. Generally, dst in C2 indicates the length of a data chunk in the source operand. The unit is 64 bytes. For the Atlas 350 Accelerator Card, dst in C2 indicates the length of a data chunk in the source operand. The unit is 32 bytes.
srcGap	Gap between adjacent data chunks of the source operand (the distance from the tail of one data chunk to the head of the next). The unit is a data block (32 bytes). The value is of the uint16_t type and must not exceed the value range of this data type. In the scenario of L1 Buffer -> Fixpipe Buffer, srcGap refers to the gap between adjacent data chunks of the source operand (the distance from the head of one data chunk to the head of the next). The unit is a data block (32 bytes). The value is of the uint16_t type and must not exceed the value range of this data type.
dstGap	Gap between adjacent data chunks of the destination operand (the distance from the tail of one data chunk to the head of the next). The unit is a data block (32 bytes). The value is of the uint16_t type and must not exceed the value range of this data type. Notes: When dst is located in C2PIPE2GM, the unit is 128 bytes. Generally, dst in C2 indicates the length of a data chunk in the source operand. The unit is 64 bytes. For the Atlas 350 Accelerator Card, dst in C2 indicates the length of a data chunk in the source operand. The unit is 32 bytes. In the scenario of L1 Buffer -> Fixpipe Buffer, dstGap refers to the gap between adjacent data chunks of the source operand (the distance from the head of one data chunk to the head of the next). The unit is a data block (32 bytes). The value is of the uint16_t type and must not exceed the value range of this data type.

Constraints

None

Returns

None

Example

For details about the calling example, see Example.

Parent topic: TPipe