SIS Documentation
SIS3820
VME Scaler
Page 25 of 79
7.4.1.3 Acquisition completed/Preset reached (IRQ source 2; edge sensitive)
The number of counting periods to acquire data can be defined with the acquisition preset
register in MCS mode. The acquisition completed interrupt source can be used to trigger an
interrupt with this condition. The interrupt is issued as soon as the preset is reached in preset
scaler mode
7.4.1.4 Overflow (IRQ source 3; level sensitive)
The overflow interrupt source is triggered if one or more counters exceed the 32-bit range.
The overflow registers can be used to identify the channel that has caused the interrupt.
Overflow interrupt generation is active in non clearing mode only.
7.4.1.5 FIFO almost full (IRQ source 4; edge sensitive)
This interrupt source can be used to catch the FIFO almost full error condition. It is set if the
fill level of the SDRAM exceeds 64 MB-512 words in FIFO mode. The condition has to be
resolved by a KEY_SDRAM_FIFO_RESET.