SIS Documentation
SIS3820
VME Scaler
Page 35 of 79
7.18.2 Input modes (Bits 18:16)
The SIS3820-SCALER board has 4 control inputs. They can be assigned to different signals
with the 3 input modes bit of the acquisision/operation mode register as listed in the table
below. All inputs can be inverted with the control inputs inverted bit of the same register.
Control Input Mode
Input assignment
Mode 0
input 1 -> no function
(bit2=0, bit1=0, bit0=0)
input 2 -> no function
input 3 -> no function
input 4 -> no function
Mode 1
input 1 -> external next pulse (LNE)/clock shadow
(bit2=0, bit1=0, bit0=1)
input 2 -> external user bit 1
input 3 -> external user bit 2
input 4 -> inhibit LNE
Mode 2
input 1 -> external next pulse (LNE) /clock shadow
(bit2=0, bit1=1, bit0=0)
input 2 -> external user bit 1
input 3 -> inhibit counting
input 4 -> inhibit LNE
Mode 3
input 1 -> external next pulse (LNE) /clock shadow
(bit2=0, bit1=1, bit0=1)
input 2 -> external user bit 1
input 3 -> external user bit 2
input 4 -> inhibit counting
Mode 4
input 1 -> inhibit counting channels 1-8
(bit2=1, bit1=0, bit0=0)
input 2 -> inhibit counting channels 9-16
input 3 -> inhibit counting channels 17-24
input 4 -> inhibit counting channels 25-32
Mode 5
input 1 -> external next pulse (LNE)
(bit2=1, bit1=0, bit0=1)
input 2 -> external HISCAL_START (time reset/start pulse)
input 3 -> no function
input 4 -> no function
Mode 6
input 1 -> external next pulse (LNE) /clock shadow
(bit2=1, bit1=1, bit0=0)
input 2 -> inhibit counting
input 3 -> clear all counters
input 4 -> external user bit 1
Modes 7 (reserved)
input 1 -> no function
input 2 -> no function
input 3 -> no function
input 4 -> no function
Note:
following LNE sources are affected by the LNE inhibit input
external LNE (front panel signal)
internal 10 MHz
channel N (ChN)
