viMoveIn8/viMoveIn16/viMoveIn32/viMoveIn64, viMoveIn8Ex/viMoveIn16Ex/viMoveIn32Ex/viMoveIn64Ex

NI-VISA 15.0 Help

Edition Date: June 2015

Part Number: 370131S-01

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Purpose

Moves a block of data from the specified address space and offset to local memory.

C Syntax

ViStatus viMoveIn8(ViSession vi, ViUInt16 space, ViBusAddress offset, ViBusSize length, ViAUInt8 buf8)

ViStatus viMoveIn16(ViSession vi, ViUInt16 space, ViBusAddress offset, ViBusSize length, ViAUInt16 buf16)

ViStatus viMoveIn32(ViSession vi, ViUInt16 space, ViBusAddress offset, ViBusSize length, ViAUInt32 buf32)

ViStatus viMoveIn64(ViSession vi, ViUInt16 space, ViBusAddress offset, ViBusSize length, ViAUInt64 buf64)

ViStatus viMoveIn8Ex(ViSession vi, ViUInt16 space, ViBusAddress64 offset, ViBusSize length, ViAUInt8 buf8)

ViStatus viMoveIn16Ex(ViSession vi, ViUInt16 space, ViBusAddress64 offset, ViBusSize length, ViAUInt16 buf16)

ViStatus viMoveIn32Ex(ViSession vi, ViUInt16 space, ViBusAddress64 offset, ViBusSize length, ViAUInt32 buf32)

ViStatus viMoveIn64Ex(ViSession vi, ViUInt16 space, ViBusAddress64 offset, ViBusSize length, ViAUInt64 buf64)

Visual Basic Syntax

viMoveIn8&(ByVal vi&, ByVal space%, ByVal offset&, ByVal length&, buf8 as Byte)

viMoveIn16&(ByVal vi&, ByVal space%, ByVal offset&, ByVal length&, buf16%)

viMoveIn32&(ByVal vi&, ByVal space%, ByVal offset&, ByVal length&, buf32&)

Resource Classes

PXI INSTR, PXI MEMACC, VXI INSTR, VXI MEMACC

Parameters

Name Direction Description

vi

IN

Unique logical identifier to a session.

space

IN

Specifies the address space. Refer to the table included in the Description section.

offset

IN

Offset (in bytes) of the starting address to read. For viMoveInXX() operations, this is a 32-bit value for 32-bit applications and a 64-bit value for 64-bit applications. For viMoveInXXEx() operations, this is always a 64-bit value.

Note Note  VISA Out and VISA In functions require the offset to begin at a value evenly divisible by the number of bytes being accessed. For example, VISA Out/In 32 requires an offset evenly divisible by 4 bytes, so valid offset values could be 0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, and so on. Values other than these return an error saying the offset is not properly aligned.

length

IN

Number of elements to transfer, where the data width of the elements to transfer is identical to data width (8, 16, 32, or 64 bits).

buf8, buf16, buf32, or buf64

OUT

Data read from bus (8 bits for viMoveIn8[Ex](), 16 bits for viMoveIn16[Ex](), 32 bits for viMoveIn32[Ex](), and 64 bits for viMoveIn64[Ex]()).

Return Values

Completion Codes Description

VI_SUCCESS

Operation completed successfully.

Error Codes Description

VI_ERROR_INV_OBJECT

The given session reference is invalid.

VI_ERROR_NSUP_OPER

The given vi does not support this operation.

VI_ERROR_RSRC_LOCKED

Specified operation could not be performed because the resource identified by vi has been locked for this kind of access.

VI_ERROR_BERR

Bus error occurred during transfer.

VI_ERROR_INV_SPACE

Invalid address space specified.

VI_ERROR_INV_OFFSET

Invalid offset specified.

VI_ERROR_NSUP_OFFSET

Specified offset is not accessible from this hardware.

VI_ERROR_NSUP_WIDTH

Specified width is not supported by this hardware.

VI_ERROR_INV_LENGTH

Invalid length specified.

VI_ERROR_NSUP_ALIGN_OFFSET

The specified offset is not properly aligned for the access width of the operation.

VI_ERROR_INV_SETUP

Unable to start operation because setup is invalid (due to attributes being set to an inconsistent state).

Description

The viMoveInXX[Ex]() operations use the specified address space to read in 8, 16, 32, or 64 bits of data, respectively, from the specified offset. These operations do not require viMapAddress() to be called prior to their invocation.

The following table lists the valid entries for specifying address space.

Value Description

VXI and VME

VI_A16_SPACE (1)
VI_A24_SPACE (2)
VI_A32_SPACE (3)
VI_A64_SPACE (4)

PXI INSTR

VI_PXI_CFG_SPACE (10)
VI_PXI_BAR0_SPACE (11) to VI_PXI_BAR5_SPACE (16)

PXI MEMACC

VI_PXI_ALLOC_SPACE (9)

For these operations, VISA ignores the attribute VI_ATTR_DEST_INCREMENT and increments the local buffer address for each element. It is valid for the VISA driver to copy the data into the user buffer at any width it wants. In other words, even if the width is a byte (8-bit), the VISA driver can perform 32-bit PCI burst accesses because it is just memory, to improve throughput.

INSTR Specific

Notice that the offset parameter to these operations for an INSTR Resource is the offset address relative to the device's allocated address base for the corresponding address space that was specified. For example, if space specifies VI_A16_SPACE, then offset specifies the offset from the logical address base address of the specified VXI device. If space specifies VI_A24_SPACE or VI_A32_SPACE, then offset specifies the offset from the base address of the VXI device's memory space allocated by the VXI Resource Manager within VXI A24 or A32 space.

Notice also that the length specified in the viMoveInXX() operations for an INSTR Resource is the number of elements (of the size corresponding to the operation) to transfer, beginning at the specified offset. Therefore, offset + length*size cannot exceed the amount of memory exported by the device in the given space.

MEMACC Specific

For a MEMACC Resource, the offset parameter specifies an absolute address.

Notice also that the length parameter to these operations for a MEMACC Resource is the number of elements (of the size corresponding to the operation) to transfer, beginning at the specified offset. Therefore, offset + length*size cannot exceed the total amount of memory available in the given space.


Related Topics

INSTR Resource

MEMACC Resource

VI_ATTR_DEST_INCREMENT

viMoveOut8/viMoveOut16/viMoveOut32/viMoveOut64, viMoveOut8Ex/viMoveOut16Ex/viMoveOut32Ex/viMoveOut64Ex

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