Addressing the Registers
To access a specific register for either read or write operations, the address of the register must be used. The HP E1418A uses both A16 and A24 register accesses.
A16 Registers Register addresses for the VXI module are found in an address space known as VXI A16. The exact location of A16 within a VXIbus master’s memory map depends on the design of the VXIbus master you are using. For the HP E1405/ E1406 Command Module, the A16 space location starts at 1F000016.
The A16 space is divided so that the VXI modules are addressed only at locations above 1FC00016 within A16. Every VXI module is allocated
64 bytes for register addresses (4016). The address of a module is determined by its logical address (set by the address switches on the module or by a write to the logical address register) times 64 (4016). In the case of the HP E1418A, the factory setting is 72 or 4816, so the addresses start at 1FD20016.
Figure
114 HP E1418A | Appendix B |