Chapter 2 Functional Description
V1553B UserÕs Manual
2.2.1.4 Control/Status Registers, Jumpers and LEDs
The V1553B possesses two configuration/status registers, the VME Configuration Register (VCR) and the 1553
Bus Configuration Register (BCR). The VME interrupt vector (b15-b9), and the IRQ level (b7-b5 for IRQ1
through IRQ7) are selectable by writing to the VCR, while the Board revision (b7-b5) and configuration (b4-b0)
can be accessed through a read of the VCR. Board revision and configuration are selectable through jumper J9. Bit
definitions for the VCR are in Tables 2.2.1.4a and 2.2.1.4b.
Table 2.2.1.4a VME Configuration Register (VCR) - Word Write
Bits b8, b3, b2, b1, b0 : Spare
Setting
Name
Description
b8, b3, b2, b1, b0
N/A
Not used
Bit b4 : Fail LED Control
Setting
Name
Description
0
FAIL_LED
LED ON (default)
1
LED OFF
Bits b7 - b5 : VME Interrupt Priority Level
Setting
Name
Description
0
Disabled (default)
1
IRQ1*
2
IRQ2*
3
IP_LV(2..0)
IRQ3*
4
IRQ4*
5
IRQ5*
6
IRQ6*
7
IRQ7*
Bits b15 - b9 : VME Interrupt Vector
Setting
Name
Description
0
I_VEC(7..0)
The number stored in this register will be presented
to the bus master when an interrupt from the
V1553B is acknowledged. Default is a value of 00.
Table 2.2.1.4b VME Configuration Register (VCR) - Word Read
Page 2-2
© 1996 PEP Modular Computers
June 22, 1998
