HP E1366A, E1367A manual Addressing the Registers, Reading the Registers, ID/Device Type Registers

Addressing the Registers

To read or write to specific registers, you must use the register address. Since the addresses for HP 75000 Series B or Series C plug-in modules are A00 through A15, use the VME A16 mnemonic for the address space. The address space within the mainframe/command module memory map depends on the mainframe/command module used. For example, the address of the HP E1300A/E1301A Mainframe starts at 1F0000h.

For the HP E1300/E1301, the A16 space is divided so modules are addressed only at locations beginning with C000h within A16. Each module is allocated 64 register addresses (40h). The module base address is related to the logical address set by the logical address switch (LADDR) on the module:

base address (h) = (logical addressh)*40h + C000h

For the RF multiplexers, the factory-set logical address is 120 (78h), so the base address = (78h)*(40h) + C000h = DE00h. Then, for example, to address the Status/Control register of an RF multiplexer in an HP E1300A/E1301A, the register address = [A16 location]h + [base address]h + [register offset]h = 1F0000h + DE00h + 04h = 1FDE04h.

Reading the Registers

ID/Device Type Registers

You can read the following RF multiplexer registers:

∙ID register (base + 00h)

∙Device Type register (base + 02h)

∙Status/Control register (base + 04h)

∙Bank 0 Channel Enable register (base + 08h)

∙Bank 1 Channel Enable register (base + Ah)

For either RF multiplexer, a read of the ID register (address base + 00h) returns FFFFh since the multiplexers are manufactured by Hewlett-Packard and are A16 only, register-based devices. The Device Type register (base + 02h) returns FF80h for the HP E1366A (50Ω) multiplexer and returns FF84h for the HP E1367A (75Ω) multiplexer.

Status/Control Register

Channel Enable Registers

Each relay requires about 15 msec execution time (close to open or open to close) during which time the RF multiplexers are “busy” . A read of the Status/Control register (base + 04h) returns FFFFh when the module is not busy or returns FF7Fh (bit 7 is low-true) when the module is busy.

A read of either of the two Channel Enable registers (base + 08h for bank 0 or base + Ah for bank 1) always returns FFFFh, regardless of the channel states.

66 HP E1366A/E1367A Multiplexer Registers Appendix B