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(i) When NW=0 (write mode), the second stack line must be followed by one (single
"write") or BLT (block transfer) data lines.
(ii) When either SLF or MRK bit is set, the VME address modifier code AM is disregarded.
The "write" data must be properly formatted, according to their endianess and their
placement on the bus. The latter is defined by values of the data strobes, A(0) (LWORD),
and A(1).
Various "write" data formatting patterns and the corresponding Mode / Address bits are
illustrated in the table below.
BE
DS1
1
0
1
0
1
1
1
0
1
0
1
0
1
1
1
0
1
1
1
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
1
0
0
Byte(0) is the least significant byte. The A(1) and A(0)/LWORD bits have to be defined
accordingly in the Address Word.
The data read from the VMEBus are either 16-bit or 32-bit wide. They are filled always from
Byte(0) in a contiguous manner. Single-byte and two-byte data are stored in 16-bit words,
while longer data are stored in 32-bit words.
Since the stack can be quite complex, it is advisable to write a proper routine or macro to set
it up. As a convenient option, one may utilize the XXUSBWin Windows application to build
the stack and save it to disk.
4.5.11 Single Transfer Commands
WIENER, Plein & Baus GmbH
DS0
A(1)
A(0)
LWORD
0
0
0
1
0
0
0
0
0
0
1
0
0
1
1
0
0
1
0
1
1
1
1
1
0
0
1
1
0
1
0
0
0
1
0
0
0
0
0
0
1
0
0
1
1
0
0
1
0
1
1
1
1
1
0
0
1
1
0
1
D31-D24
D23-D16
Byte(0)
Byte(1)
Byte(0)
Byte(1)
-
Byte(1)
-
Byte(1)
-
-
-
-
-
-
-
-
-
-
-
-
Byte(3)
Byte(2)
Byte(2)
Byte(1)
-
Byte(3)
-
Byte(2)
-
-
-
-
-
-
-
-
-
-
-
-
28
D15-D8
D7-0
Byte(2)
Byte(3)
Byte(2)
-
Byte(2)
Byte(3)
Byte(2)
-
Byte(2)
Byte(3)
Byte(0)
Byte(1)
-
Byte(3)
Byte(2)
-
-
Byte(1)
Byte(0)
-
Byte(1)
Byte(0)
Byte(0)
-
Byte(2)
Byte(1)
Byte(1)
-
Byte(3)
Byte(2)
Byte(1)
Byte(0)
-
Byte(0)
Byte(1)
-
-
Byte(2)
Byte(3)
-
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