PantherPro/46 Image Recorder
TP8251
October 1995
PrePRESS SOLUTIONS CONFIDENTIAL
3-9
the Scan Line FIFO.
The Dual Port Video Memory must be reset before each image.
B. Scan Line FIFO
The Scan Line FIFO is 16 bits wide. It provides a full scan line of buffering at the highest
resolution. Writes into the FIFO occur as a two-clock (minimum) cycle at the system clock rate.
This will allow the FIFO logic to generate a "Full" signal which can stifle subsequent writes.
Data from the Video FIFO is read one byte at a time, as needed to load the video shift
register.
The FIFO "Retransmit" signal is used to repeat scan lines during Quality Mode. This requires
the hardware to reset the FIFO before each scan line. Upon reset, the Dual Port Video
Memory (DPVM) transfers one full scan line into the Scan Line FIFO, and then outputs the
scan line in real time to the video shift register. If the scan line is to be repeated, the scan line
is retransmitted from the Scan Line FIFO. The process is repeated for the next scan line.
C. Xcount
An Xcount register and counter contains the number of words per scan line, counting the
words transferred into the Scan Line FIFO. When the full number of words is reached,
transfers stop with the Scan Line FIFO holding a complete scan line. The Xcount register
requires loading once per image.
D. Margin and Blanking
A programmable margin is provided by the Margin Register. For each scan line, a margin
counter is loaded with the margin register contents and counted down to zero. The video is
blanked, and reading from the FIFO is inhibited until the this margin is exhausted. Once
reading from the FIFO commences, the real video is output till the right edge of the media is
reached, and the video is again held blank.
E. Fill
A fill feature allows blank scan lines to be output without fetching of video data. This allows
images to be transmitted to the PantherPro/46 without the corresponding "blank" data. The fill
feature supports automatic blanking at a granularity of single scan lines.
F. Video Control
Circuitry will count pixels, load the shift register, and issue reads to the Scan Line FIFO at
appropriate times. This circuitry is collectively known as video control.
G. Test Pattern
Capability to substitute a hardware generated test pattern for normal video is provided. Each
square of the test pattern measures 128 pixels square.
H. Serialization
Video output to the laser amplifier is a serial stream. Bytes of video from the Scan Line FIFO
is serialized in a shift register and then turned into a stream of pulses before being output to
the High Speed Laser Amplifier PCB.