User`s manual

Chapter 3
Using the Agilent E1490C
This chapter shows how to use the backplane interface circuitry on the
Agilent E1490C Breadboard Module. This chapter includes:
• Reading Data From Registers . . . . . . . . . . . . . . . . . . . . . . . . Page 51
• Writing Data to the Control Register. . . . . . . . . . . . . . . . . . . Page 54
• Using Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 57
• Resetting the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 59
• Detecting Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 59
• Using Other Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . Page 60
• Example Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 61
Reading Data From Registers
The breadboard module contains circuitry for three readable registers as
defined by the VXIbus Specification:
– Status Register
– ID Register
– Device Type Register
Status Register Bit
Definitions
Table 3-1 shows the Status Register bit definitions. It will be used as an
example of how to read from a register on the breadboard module. As
shown in Table 3-1, only four of the sixteen bits in the register are
predefined by the VXIbus Specification. The other twelve bits are "device
dependent". That is, they can represent any condition that you define.
The inputs to the Status Register are provided by the user from the custom
circuitry on the module. Access points (STATUS 0 - 15 on the component
side of the module and TP184 - TP198 on the trace side) are provided on the
module to tie into the Status Register, as shown in Figure 3-1. See pages 36
and 52 for additional information on using the Status Register.
Table 3-1. Status Register Bit Definitions
Data Bit(s) Definitions
SR0 - SR1 Device Dependent (user assignable)
SR2 (0 = failed/executing Self-test; 1 = passed Self-test)
SR3 Ready
SR4 - SR13 Device Dependent (user assignable)
SR14 (0 = module selected by MODID high, 1 = not by MODID)
SR15 Device Dependent for A16 device
Chapter 3 Using the Agilent E1490C 51