HP E1418A - Manual (Page 127)

Register Descriptions
Manufacturer ID
Register
The Manufacturer ID Register is a VXIbus required register. A read of this
register returns CFFF
16
(-12289 decimal).
Address
Base + 00
16
Bit Position 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Setting 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1
READ Device
Class
Address
Mode
Manufacturer’s ID Code
Device Class: The HP E1418A is a register-based device.
Address Mode: The HP E1418A uses the A16/A24 address mode.
Manufacturer ID Code: Identifies Hewlett-Packard as the device
manufacturer.
Logical Address
Register
The module supports Dynamic Configuration. The module’s logical
address is set in bits 0 through 7 of the Logical Address Register.
Address
Base + 00
16
Bit Position 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Setting Undefined 00
16
–FF
16
WRITE Undefined Logical Address Setting
Logical Address Setting: Bits 0 through 7 of this register is set by either:
– the logical address switch settings following power-up or system reset,
or
– by a write to this register during Dynamic Configuration.
When bits 0–7 are set to a value of 255 (FF
16
) the device is available for
selection via Dynamic Configuration, and when MODID is asserted the
module will respond. Typically, this is only done once at power-up or
system reset and the desired logical address is written into the register bits 0
through 7. With any other Logical Address Register setting, the module
will not be accessible via MODID. The content of this register is compared
with address lines 6 through 13 from the backplane to determine module
accesses in A16 space.
Note Writes to this register can be made at any time and will change the logical
address of the module for later accesses.
126 HP E1418A Register-Based Programming Appendix B
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