Vactivestrtstop – Cirrus Logic EP93xx User Manual

Page 221

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DS785UM1

7-39

Copyright 2007 Cirrus Logic

Raster Engine With Analog/LCD Integrated Timing and Interface

EP93xx User’s Guide

7

7

7

When the Vertical counter counts down to the written
STOP value, the VSYNC signal on the V_CSYNC pin will
go inactive if CSYNC = ‘0’ and SYNCEN = ‘1’ in the

VideoAttribs

register. Please refer to the video signalling

timing diagrams shown in

Figure 7-9

and

Figure 7-10

.

STRT: Start

-

Read/Write

When the Vertical counter counts down to the written
STRT value, the VSYNC signal on the V_CSYNC pin will
go active if CSYNC = ‘0’ and SYNCEN = ‘1’ in the

VideoAttribs

register.

VActiveStrtStop

Address: 0x8003_0008

Default: 0x0000_0000

Definition: Vertical Active Start/Stop register

Bit Descriptions:

RSVD:

Reserved - Unknown during read

STOP:

Stop - Read/Write

The STOP value is the value of the Vertical down counter
at which the VACTIVE signal becomes inactive (stops).
This indicates the end of the active video portion for the
Vertical frame. Please refer to the video signalling timing
diagrams in

Figure 7-9

and

Figure 7-10

. VACTIVE is an

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

STRT:

Start - Read/Write

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

Figure 7-9

and

Figure 7-10

. VACTIVE is an

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

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25

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23

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19

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16

RSVD

STOP

15

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13

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7

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5

4

3

2

1

0

RSVD

STRT

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