HP E1418A manual Figure B-3. A24 Windowing into the A16 Registers

A16/A24 Windows By using window addressing, you can control the A24 space registers by mapping them onto the upper 16 of the A16 registers. This allows full control of the HP E1418A using only A16 addressing. Figure B-3 shows the A24 mapping into A16 space.

In practice, four bits (A24_Window Value) in the A16 Card Control

Register (base + 1E16) control which A24 registers map to the A16 space.

For example, if the A24_Window Value is set to 0010, the 16 Main_DAC

Write Immediate Registers are mapped to the A16 space. The Card Control

Register is described in more detail on page 137.

Figure B-3. A24 Windowing into the A16 Registers

116 HP E1418A Register-Based Programming Appendix B