INDUSTRIAL I/O PACK SERIES AVME9675A
VME64x bus 6U CARRIER BOARD
Acromag, Inc. Tel: 248-295-0310
- 14 - http://www.acromag.com
- 14 -
https://www.acromag.com
16
Open
GND
Open
Open
Open
Open
17
GND
GND
Open
Open
Open
GND
18
GND
GND
Open
Open
GND
Open
19
Open
GND
Open
Open
GND
GND
20
GND
GND
Open
GND
Open
Open
21
Open
GND
Open
GND
Open
GND
The AVME9675A board has pull-up resistors tied to each of the six
geographic addres
s inputs, so that their state (Open = “high” or GND =
“low”) can be interpreted by logic on the carrier board. This logic uses the
geographic addressing inputs to encode the base address of the CR/CSR
space into the CR/CSR Base Address Register (BAR). The host computer
can locate the AVME9675A by scanning the A24 CR/CSR space using
address modifier 2FH (refer to section 3 for CR/CSR space programming
details).
Once located, additional characteristics of the AVME9675A may be read
from the Configuration ROM (CR) portion of the space. Following power
up, accesses to the card’s Short I/O (A16) space are disabled. The base
address of the carrier in the Short I/O space and the desired address
modifier must be programmed using the Function 0 Address DEcoder
CompaRe (ADER) Register in the Control/Status Register (CSR) portion of
the CR/CSR space. Then, accesses to the Short I/O space can be enabled
by writing to the Bit Set Register in the CSR. Each carrier board
implements a 1K byte block of addresses in the Short I/O space.
•
Consult your host CPU manual for detailed information about
addressing the VME64x bus short I/O (A16, 16-bit) space. In many
cases, CPU's utilizing 24-bit addressing will start the 16-bit address at
FF0000 (Hex), and 32-bit CPU's at FFFF0000 (Hex).
2.6 VMEbus Address Modifiers
No hardware jumper configuration is needed. The carrier board initially
responds to address modifier 2FH in the standard (A24) CR/CSR space.
Following configuration within the CR/CSR space the carrier board will
respond to either address modifier 29H or 2DH in the VME64x bus Short
(A16) I/O space. This means that both short supervisory and short non-