Matrox Solios eA, Установка и справочник по оборудованию, Страница: 83 / 196

Matrox Solios eA/XA acquisition section 83
Clock
Each PSG can accept or provide one pixel clock signal (slave or master mode).
Important When accessed from the analog video input connectors (DVI), the pixel clock,
composite/horizontal synchronization, and vertical synchronization signals of
each PSG form a group of signals. The signals of each group shares the same
direction (input or output) and same signal format (TTL or LVDS). When
accessed from the internal or external auxiliary I/O connectors (HD-44), the
format and direction of the synchronization signals are independent; the board
can both transmit and receive synchronization signals at the same time.
Exposure timers
Each PSG has two exposure timers. These timers can each generate a exposure
output signal with up to two pulses; exposure output signals allow you to control
the exposure time and other external events related to the video source (such as a
strobe). The exposure signals can be output using auxiliary output signals.
The exposure timers are 24-bit timers, allowing each to count up to 16777215
clock ticks before resetting.
The exposure timers can use one of the following as a clock source:
• A clock that is internally generated. Each exposure timer can use its PSG’s clock
generator, which can generate a single clock with a programmable frequency of
0.8 to 100 MHz. Timers can only use the clock generator of their own PSG.
• A clock from an external source. In this case, you must define the appropriate
auxiliary input signal as a timer-clock input; the timer-clock input signal must
meet the specification of the auxiliary signal. The same timer-clock input can be
used to clock both timers of a PSG.
• A clock based on another exposure timer of the same PSG.
• A clock based on an external pixel clock signal.
• A clock based on the HSYNC or VSYNC signal generated by the PSG.
To output an exposure signal, use the MIL-Lite function MdigControl() with
M_GRAB_EXPOSURE . Set the clock source of an exposure timer in the DCF .