User`s manual

Each bit in the ID Register is normally pulled high (1) by RP5 and RP6.

The bits can be reconfigured low by closing the appropriate switch (SP2 and

SP3). If no switches are closed (that is, all bits are high or 1’s) from Tables 2-5

and 2-6, the module will be defined as a register-based and A16 device and

will have a Manufacturer ID code of 4095 (Agilent Technologies).

Table 2-5. Breadboard Addressing Mode

Value Addressing Mode

00 A16/24

01 A16/32

10 RESERVED

11 A16 Only

Table 2-6. Breadboard Device Classification

Value Device Class

00 Memory

01 Extended

10 Message Based

11 Register Based

See Chapter 3 for additional information on using the ID Register. Refer to

the VXIbus System Specification, Section C.2.1.1.2, for detailed information

concerning ID Register implementation restrictions.

Device Type

The Device Type Register is a 16-bit register which contains a

device-dependent "module type" identifier and a "memory required" field

(for A24 and A32 devices only). These two fields are set on the module by

the use of switches (SP4, SP5) on the inputs to the data bus line drivers U14

and U13, as shown in Figure 2-23.

Each bit in the Device Type Register is normally pulled high (1) by RP7 and

RP8. The bits can be reconfigured by closing switches SP4 and SP5. The

range of device types for an A24 or A32 device is 0 - 4095. For an A16 device,

all 16 bits are available for specifying the device type for a range of 0 - 65535.

Note Per the VXIbus System Specification (OBSERVATION C.2.6), module

codes 0 - 255 are reserved for Slot 0 devices.

38 Configuring the Agilent E1490C Chapter 2