VXI TECHNOLOGY SVM2608 - Manual (Page 52)

VXI Technology, Inc.
52 SVM2608 Programming
Write 0x0D40 @ Base address + 0xC00062
Method 2: Make one 32 bits write.
Write 0x00030D40 @ Base address + 0xC00060
Example 3: Setting Channel 2 to Pre-acquire 100,000 Samples
The acquisition of samples starts when a trigger point is met or when a trigger is forced by setting
the corresponding Force bit. However, samples can be collected before the occurrence of the
trigger point. These samples are called Pre-Trigger Points. The number of Pre-Trigger Points to be
acquired is determined by the value programmed in the Pre-Trigger Points register of the
respective channel.
In hexadecimal format, 100,000 corresponds to 0x186A0. The Pre-Trigger Points register for
Channel 2 is composed of two 16-bit registers located at offsets 0xC00064 (the MS, bits D19 -
D16) and 0xC00066 (the LS, bits D15 - D0).
Method 1: Make two 16 bits writes.
Write 0x0001 @ Base address + 0xC00064
Write 0x86A0 @ Base address + 0xC00066
Method 2: Make one 32 bits write.
Write 0x000186A0 @ Base address + 0xC00064
The total number of samples acquired is set by the Sample Points, and the number of samples
stored after the trigger event is:
(Sample Points) – (Pre-Trigger Points)
Note Pre-Trigger Points must be less than Sample Points (Pre-Trigger Points < Sample Points).
Example 4: Setting Channel 2 to Delay Acquisition by 1,500,000 Samples
The acquisition of samples starts when a trigger point is met or when a trigger is forced by setting
the corresponding Force bit. If the acquisition is to be triggered by a trigger event (signal trigger,
external trigger or forced trigger) the first sample is collected either immediately, within one
sample clock period from the moment when the trigger occurs or after a Delay Period. The Delay
Period is determined by the value programmed in the Trigger Delay register of the respective
channel. The Delay Period is based on the Sample Rate value. If the value in the Trigger Delay
register is set to zero, the sampling starts immediately after the trigger event. If the Trigger Delay
register is set to 100 (0x64), for example, then Sample Zero is taken 100 sample clocks after the
trigger event.
In hexadecimal format, 1,500,000 corresponds to 0x16E360. The Trigger Delay register for
Channel 2 is composed of two 16-bit registers, located at offsets 0xC00068 (the MS, bits D31 -
D16) and 0xC0006A (the LS, bits D15 - D0).
Method 1: Make two 16 bits writes.
Write 0x0016 @ Base address + 0xC00068
Write 0xE360 @ Base address + 0xC0006A
Method 2: Make one 32 bits write.