Technical Appendix - Sony DXC-990 Manual

12. Technical Appendix

12. TECHNICAL APPENDIX
WEN pulse -output signal to external frame memory-
The DXC-990/990P and DXC-390/390P feed the WEN pulse output to the external frame memory so that
the external frame memory can precisely store the video signal output from the DXC-990/990P and
DXC-390/390P. The purpose of this output pulse is to externally lock the frame memory timing to the
HD/VD signal or the sync signal of the DXC-990/990P and DXC-390/390P so that the right start time of
the external frame memory can be precisely controlled by this signal. In short, this output pulse indicates
that the video signal following the edge of this pulse is the valid video signal.
The DXC-990/990P and DXC-390/390P have three functions using the WEN pulse such as Normal
operation, Strobe mode and Long term exposure mode.
Normal operation
During normal operation of a camera, the WEN pulse continuously outputs a high signal for even fields, low signal
for odd field or vice versa (See diagram). This means that the output pulse is a field index pulse.
WEN
Video
E O
Strobe mode
DXC-990/990P or DXC-390/390P
When the
the odd field only (See diagram of Strobe function). An external frame memory can store a complete still picture
the moment the WEN pulse is used with an external frame memory. WEN mode is selectable from WEN 1-3 for
DXC-990/990P. Only WEN1 mode is available for DXC-390/390P.
Long term exposure mode
During the long term exposure mode, the video signal is output as shown in the diagram below, and the WEN
pulse is output during the field before the valid video field (See diagram of Strobe function). The shutter speed
must be set beforehand by using the menu.
WEN
Video
38 – DXC-990/990P, DXC-390/390P Sales Manual
E O E
is operating in the Strobe mode, the WEN pulse outputs during
O E
Note: It is impossible to use both the Strobe mode and Long term exposure at the same time.
O E O
O
E O E
E
In case of 2 FRM, shutter speed
O