Reads data from a specified VXI address with the specified access mode.
[ lStatus = ] VxiIn ( lMode, lAddress, lWidth, plResult )
The VxiIn procedure syntax has the following parts:
|
Name |
Type |
Description |
|
lStatus |
Long |
Status |
|
lMode |
Val Long |
Access mode |
|
lAddress |
Val Long |
VXI address within the specified space |
|
lWidth |
Val Long |
Width in bytes of response (1, 2 or 4) |
|
plResult |
Var Long |
Response value |
This function may be used when a direct read from a VXI bus address is required.
The iMode parameter is specified as follows:
Bits 0,1 - VXI address space:
|
1 |
A16 |
|
2 |
A24 |
|
3 |
A32 |
Bits 2,3,4 - Access Privilege:
|
0 |
Nonprivileged data access |
|
1 |
Supervisory data access |
|
2 |
Nonprivileged program access |
|
3 |
Supervisory program access |
|
4 |
Nonprivileged block access |
|
5 |
Supervisory block access |
Bit 7 - Byte Order:
|
0 |
Motorola (MSB first) |
|
1 |
Intel (LSB first) |
All other bits should be 0.
If lStatus is negative, an error has occurred. Otherwise, the function is successful.
The following command reads the ID register of a device at Logical Address 4, and the response is assigned to the variable lResult:
VxiIn (1, 0xC100, 2, lResult)