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Hblankstrtstop – Cirrus Logic EP93xx User Manual

Page 226

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7-44

DS785UM1

Copyright 2007 Cirrus Logic

Raster Engine With Analog/LCD Integrated Timing and Interface
EP93xx User’s Guide

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7

STRT:

Start - Read/Write

The STRT value is the value of the Horizontal down
counter at which the HACTIVE signal becomes active
(starts). This indicates the start of the active video portion
for the Horizontal line. Please refer to video signalling
timing diagrams in

Figure 7-9

and

Figure 7-10

. HACTIVE

is an internal block signal. The active video interval is
controlled by the logical OR of VACTIVE and HACTIVE.

HBlankStrtStop

Address: 0x8003_022C

Default: 0x0000_0000

Definition: Horizontal Blank signal Start/Stop register

Bit Descriptions:

RSVD:

Reserved - Unknown during read

STOP:

Stop - Read/Write

The STOP value is the value of the Horizontal down
counter at which the HBLANK signal becomes inactive
(stops). This is used to generate the BLANKn signal that is
used by external devices to indicate the end of the active
video portion for the Horizontal line. Please refer to video
signalling timing diagrams in

Figure 7-9

and

Figure 7-10

.

HBLANK is an internal clock signal. The BLANKn output is
a logical AND of VBLANK and HBLANK.

STRT

:

Start - Read/Write

The STRT value is the value of the Horizontal down
counter at which the HBLANK signal becomes active
(starts). This is used to generate the BLANKn signal that is
used by external devices to indicate the start of the active
video portion for the Horizontal line. Please refer to video
signalling timing diagrams in

Figure 7-9

and

Figure 7-10

.

HBLANK is an internal clock signal. The BLANK output is
a logical AND of VBLANK and HBLANK

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RSVD

STOP

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1

0

RSVD

STRT