HP E1459A Status/Control Register, Device Type Register, Manufacturer ID Register

Manufacturer ID Register

ID register (base = 00h) is a read only register. For the Isolated Digital Input/Interrupt, a read of the ID register returns FFFFh since the multiplexers are manufactured by Hewlett-Packard and are A16 only, register-based devices.

Manufacturer ID Register (base + 00h)

b + 0h	15	14	13	12	11	10	9		8	7	6	5	4	3	2	1	0
Write								No Effect
Read							Manufacturer ID

Device Type Register

* Returns FFFFh = Hewlett-Packard A16 (only) register-based device

Device Type register (base = 02h) is a read only register. For the Isolated Digital Input/Interrupt, a read of the Device Type register returns 0154h. This indicates it is a model HP E1459A.

Device Type Register (base + 02h)

b + 2h	15	14	13	12	11	10		9		8	7	6	5	4	3	2	1	0
Write									No Effect
Read							Always Returns 0154h

Status/Control Register

Status/Control register (base = 04h) can be read and written. Many of the bits perform control functions. Reading this register returns the current state of the status bits for the module.

Status/Control Register (base + 04h)

b + 4h	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
Write					Undefined					D	I	BS	Undefined			R
Read	Undefined	M		Undefined			D IRQ	E IRQ	Undefined	D	I	BS	Undefined			R

NOTE: Bits 8 and 9 are returned in the IACK response in the same bit positions.

WRITE

R = Reset to power-on state by writing a "1" in this bit (Must be set back to "0").

BS = Bank Select. When "0" Port 0 and Port 1 data are accessed in registers b + 10h through b + 2Eh. When "1" Port 2 and Port 3 data are accessed in the same registers.

I = Interrupt Enable. When set to 1, an IRQ can be generated with an edge event (assuming one is enabled).

D = Data Ready Enable. When set to 1 an IRQ can be generated with a DAVX line is asserted.

78 HP E1459A Register Definitions