Agilent Technologies L4400 Podręcznik Użytkownika Pobierz pdf (Strona 227)

L4450A 64-Bit Digital I/O with Memory and Counter 8

L4400 User’s Guide 215

Byte Ordering

When using buffered memory operations, the width of the data sets how

the memory data is interpreted. Changing the width of the first channel in

a bank invalidates any traces stored or captured.

Output Operations For output operations (see page 210), traces are put

into memory using the TRACe:DATA:DIGital command.

For output operations, the data stored in memory is output as follows:

• BYTE output - first byte in memory on the first handshake, next byte in

memory on the second handshake, and so on.

• WORD output - first and second byte in memory on the first handshake,

next two bytes in memory on the second handshake, and so on.

• LWORd output - first four bytes in memory on the first handshake, next

four bytes in memory on the second handshake, and so on.

Note that for WORD outputs the first byte in memory is considered the

most significant byte and is output on the upper bits (15 through 8). For

LWORd outputs the first byte is output on bits 31 through 24.

You can change the byte order reported using the FORMat:BORDer

command. This command allows you to swap the most- significant and

least- significant byte ordering for all data transfer operations. The

command is applied globally and cannot be assigned to an individual slot

or channel.

Input Operations For input operations (see page page 212), bytes are read

into memory as follows:

• BYTE input - the first byte in memory was read on the first handshake,

the next byte in memory was read on the second handshake, and so on.

• WORD input - first and second byte in memory were read on the first

handshake, next two bytes in memory were read on the second

handshake, and so on.

• LWORd input - first four bytes in memory were read on the first

handshake, next four bytes in memory were read on the second

handshake, and so on.

Note that for WORD inputs the first byte in memory is considered the most

significant byte and was read on the upper bits (15 through 8). For

LWORd

inputs the first byte was read on bits 31 through 24.

1 2 ... 222 223 224 225 226 227 228 229 230 231 232 ... 280 281

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Agilent Technologies L4400 Podręcznik Użytkownika Strona 227