HP E1418A manual Register Descriptions, Manufacturer ID Register, Logical Address Register

Register Descriptions

Manufacturer ID Register

The Manufacturer ID Register is a VXIbus required register. A read of this register returns CFFF16 (-12289 decimal).

Address	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
Base + 0016
	READ	Device		Address						Manufacturer’s ID Code
		Class		Mode

Logical Address Register

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.

The module supports Dynamic Configuration. The module’s logical address is set in bits 0 through 7 of the Logical Address Register.

Address	Bit Position	15	14	13	12	11	10	09	08	07	06	05	04	03	02	01	00
	Setting				Undefined								0016–FF16
Base + 0016
	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