Model VM32PAFF
32 Channel VME Module
Programmable Amplifier
Programming
With Fixed Frequency Filter
5.
Programming
Register Level Programming
A register-based read/write programming interface makes the VM32PAFF family of VMEbus amplifier/filter
boards extremely easy to program. All the programmable gain modules on the motherboard may be
programmed through three 16-bit registers. These are the Channel Address Register, the Data Register,
and the Reset Register.
Figure 5-
1 shows the VM32PAFF VMEbus memory map.
(MSB)
B15
B08
B07
(LSB)
B00
BUSY
0
0
0
0
0
0
0
0
0
0
CH4 CH3 CH2 CH1 CH0
‘0’ indicates bit always reads zero
Binary address of channel selected for
Write data is ignored
data read or write operation.
00000 = Channel 0
00001 = Channel 1
11110 = Channel 30
BUSY interlock:
11111 = Channel 31
‘1’ indicates on-board serial channel is busy formatting
and transferring data.
Automatically sets to ‘1’ upon writing gain data to DATA and upon writing to RESET.
User writes ‘1’ to initiate readback og gain setting for channel pointed to by CH[4:0].
Automatically clears when transfer to/from the selected channel is complete.
(MSB)
B15
B08
B07
(LSB)
B00
0
0
0
0
0
0
0
0
0
0
0
0
G3
G2
G1
G0
‘0’ indicates bit always reads zero
Binary representation of channel gain, in 6dB steps.
Write data is ignored
Writing data to these bits when BUSY is
clear sets the gain of the channel pointed
to by CH[4:0],. When readback of a channel’s
gain setting is requested by setting BUSY
along with CH[4:0], the current channel
gain setting appears here once BUSY clears.
(MSB)
B15
B08
B07
(LSB)
B00
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Any write to this location (word or byte) causes all channels to reset to the minimum gain, using the BUSY interlock.
The data written is irrelevant. Reading this location will return random data.
Immediately after a write to RESET completes (BUSY = 0), data read back in DATA, for any channel, will be 0x0000.
Figure 5-1: VM32PAFF VMEbus Memory Map.
15
The memory map consists of three VMEbus 16-bit registers.
1784 Chessie Lane., Ottawa, IL 61350
•
Tel: 800/252-7074, 815/434-7800
•
FAX:815/434-8176
e-mail: [email protected]
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Web Address: http://www.freqdev.com
