HP FET MULTIPLEXER E1351A/53A manual A16 Address Space Outside Command Module Or Mainframe

The Base Address When reading or writing to a multiplexer register, specify a hexadecimal or decimal register address. This address consists of a base address plus a register offset. The base address used programming depends on whether the A16 address space is outside or inside the HP E1405A/E1406A Command Module or HP E1300A/E1301A Mainframe.

A16 Address Space

Outside the

Command Module

or Mainframe

When the command module or mainframe is not part of your VXIbus system (Figure B-1), the multiplexer’s base address is computed as:*

C00016 + (LADDR * 64)16

or

49,152 + (LADDR * 64)

where C00016 (49,152) is the starting location of the register addresses, LADDR is the multiplexer’s logical address, and 64 is the number of address bytes per VXIbus device. For example, the multiplexer’s factory set logical address is 112. With this address, the multiplexer has a base address:

C00016 + (112 * 64)16

C00016 + 1C0016 = DC0016

or (decimal)

49,152 + (112 * 64)

49,152 + 7,168 = 56,320

A16 Address Space

Inside the

Command Module

or Mainframe

When the A16 address space is inside the command module or mainframe (Figure B-2), the multiplexer’s base address is computed as:

1FC00016 + (LADDR * 64)16

or

2,080,768 + (LADDR * 64)

where 1FC00016 (2,080,768) is the starting location of the VXI A16 addresses, LADDR is the multiplexer’s logical address, and 64 is the number of address bytes per register-based device. Again, the multiplexer’s factory set logical address is 112. If this address is not changed, the multiplexer will have a base address of:

1FC00016 + (112 * 64)16 1FC00016 + 1C0016 = 1FDC0016

or

2,080,768 + (112 * 64)

2,080,768 + 7,168 = 2,087,936

* The "16" at the end of the address indicates a hexadecimal number.

Appendix B HP E1351A/53A Register-Based Programming 83