Addressing the Registers

Access to the digitizer’s registers is through addresses mapped into A24 address space. At power-on, the system resource manager (HP E1406) reads the digitizer’s Device Type register (in A16 address space) to determine the amount of A24 memory the digitizer needs (4096 bytes). The resource manager allocates a block of A24 memory to the digitizer and writes the base (starting) address into the digitizer’s Offset register (also in A16 space).

Figure C-1 is an example of how the HP E1406 resource manager maps the digitizer registers into A16 and A24 address space.

Figure C-1. HP E1429A/B A24 Address Space

Appendix C

Register Programming 343

Page 343
Image 343
HP manual Addressing the Registers, Figure C-1. HP E1429A/B A24 Address Space