The DIO-II module is a multimode digital source and capture unit. In Low Speed Mode it provides a 20-bit parallel or 24-bit serial I/O capability running at speeds up to 50 MHz. In High Speed Mode, the DIO-II provides a 16-bit parallel I/O capability up to 200 MHz. In both Modes, the Clock is generated by a low jitter PLL source that is capable of generating clocks from 320 kHz up to 1 GHz. In low speed mode the maximum usable clock frequency is 100 MHz, in High Speed mode the maximum clock frequency via the backplane is 600 MHz and via the front clock 1 GHz.

The DIO-II supports external clocking (in or out), external trigger and frequency synchronization with an external reference source. The DIO-II offers 8 Pattern Bits to the user for DUT synchronization and control. The remaining 8 Pattern Bits are used for control and synchronization of the analog source and capture modules through the ATX backplane. The flexible pattern bit structure enables the implementation of various serial protocols as SPI, I2C, I2S, etc. This ensures coherent mixed-signal measurements thereby improving the accuracy of your measurement without need for "post-process" windowing.

Block Diagram

Key Features

  • Multimode Digital Source/Capture module
  • Very low jitter clock generation
  • Up to 50 MHz data rate in low speed mode
  • Up to 200 MHz data rate in high speed mode
  • Up to 1 GHz clock rate via front clock out
  • 20-bit parallel / 24-bit serial capture capability
  • 128k x 16 pattern generator (low speed mode)
  • Programmable clock delays (high sp. mode)
  • Programmable IO levels
  • Exclusively for ATX series hardware platform

Technical Specifications

Low Speed Mode

Pattern Generator 100 MHz, 128kwords x 16-bits
Data I/O Pins 20-bit parallel / 24-bit serial
Data I/O Formats parallel, byte-by-byte, serial
Source/Capture Depth 4M-words x 24-bits/8M-words x 16 bits
Internal clock frequency 320 kHz to 100 MHz
External clock frequency DC to 100 MHz
Data source/capture rate DC to 50 MHz
I/O Levels VIL: 0.4 V (max), VIH: 1.2 V, 1.8 - 3.3 V

Front panel clocks

Clock output level (typical) 1.5 Vpp / 50 Ω
Clock output frequency 320 kHz - 1 GHz
Clock input Low Speed mode DC - 100 MHz
Clock input High Speed mode 1 MHz - 400 MHz (ref. clock in)
Clock input threshold / imp. 0 V or 1 V (programmable) / 50 Ω

High Speed Mode

Data I/O Pins 16-bit
Data I/O Formats parallel
Source/Capture Depth 8M-words x 16-bits
Backplane clock frequency 320 Hz to 600 MHz
Data source/capture rate DC to 200 MHz
I/O Levels LVDS

Separate Stimulus clock, Capture clock and DUT clock. All derived from the same low jitter main clock


Clock jitter (typical @ 100 MHz) 190 fs
Independent delay per clock 0-32 ns (~0.5 ns resolution)
Trigger input threshold level 1 V (1 kΩ)
Pattern bit trigger capability DC - 5 MHz