The GX5296 can operate at frequencies up to 125 MHz with programmable timing sets applied on a per Step and Channel basis. Each board contains 32 I/O pins and each pin can be configured as an input or output on a per vector basis. Each board supports up to 4K Steps and 64M Vectors. A Vector represents the drive, expect, mask, and Tri-State data for one state (one Vector per clock cycle). The Vector states are represented as ASCII characters.
A Step is a higher level that includes clock, timing, and control settings as well as a pointer into the Vector Memory. Different Steps can have overlapping Vector ranges (Vector Count and Offset). Each Step contains timing set information that will be applied to the relevant vectors.
A Timing Set consists of a Drive Phase Assert, and Return edge as well as a Capture data on a Window Open or Close edge. The Phase edges determine when a Vector state will be loaded within a clock cycle. The Window edges determine when the input will be sampled within a clock cycle. Consequently, each channel has an associated capture mode that allows the sequencer to capture an input on the Window’s open edge or close edge.
The GX5296 includes a unified (Vector) memory, for storing drive, expect, mask, and Tri-State data for each of the 64M Vectors. A separate Record memory is used to store up to 64M response states (raw logic HI and LO) or real time compare error states (depending on a Step’s record mode) which are recorded during a sequencer run. In addition, the GX5296 includes a 1K deep error memory which is used in conjunction with the real time compare (RTC) function for recording compare errors and the address of the error.
One of the GX5296’s functional modules is the sequencer. The GX5296 sequencer functions as a state machine with five states: RUN, PAUSE, HALT, STANDBY, and RESET. The sequencer runs each Step sequentially, applying timing (phase and window) settings to the Vectors associated with the Step. The sequencer also performs a conditional jump, unconditional jump, subroutine jump, or loop if so instructed by a Step.
The sequencer has the ability to Handshake with various signals in order to synchronize with a UUT. Handshaking settings can be selected on a per Step basis where various Handshake Pause and Resume resources can be used. Handshake resources are configured for use by a Step. Configuring a Handshake resource entails selecting a source signal and test condition (high level, low level, rising edge, falling edge) to evaluate the source signal as a valid Pause or Resume condition.
Each digital pin can be individually programmed for a drive high, drive low, input threshold high, input threshold low, and a load value (with commutation voltage level). Each channel output can be formatted programmatically to one of the following formats: No Return, Return to Off (HiZ), Return to Zero, Return to One, Return to Complement, Surround Complement, Force Zero, Force One, Force Off (HiZ), Force inverse Phase Output, Force Phase Output. Output formatting provides flexibility to create a variety of bus cycles and waveforms to test board and box level products.
Each channel has its own Parametric Measurement Unit (PMU). The PMU offers the ability to perform analog measurements on each digital pin. Measurement configurations include force voltage, measure current and force current, measure voltage.
Additionally, under software control, each channel’s pin electronics operating temperature, drive high / drive low voltages, and sense hi / sense lo voltages can be monitored and measured.
Each channel’s source and sink load currents can be set programmatically. The channel’s current source forces the specified constant current to be active when the input voltage is above the high (or low) voltage clamp value. Each input channel’s constant current voltage clamp can be set programmatically. With independent high and low clamping (commutating) voltages, the source and sink currents each have their own commutation voltage level. In addition, each channel can be programmed to a termination voltage value (VTT). Note that VTT and VComm share a common voltage source, which allows only one mode to be supported for each channel.