7.7.2 Video Output registers details
7.7.2.1
VOnLCDTIMING0 - Horizontal axis panel control register
This register specifies the synchronization and data timining of a line by the
following:
•
horizontal synchronization pulse width in pixels
•
horizontal front porch width in pixels
•
horizontal back porch width in pixels
•
pixels/line
The time of one pixel is the period of VOnCLK, i.e. T
VOnCLK
= 1/f
VOnCLK
.
Access
This register can be read/written in 32-bit units.
Address
<VOn_Base> + 000
H
Initial Value
0000 0000
H
. This register is initialized by any reset.
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
HBP[7:0]
HFP[7:0]
R/W
R/W
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
HSW[7:0]
PPL[5:0]
0
0
R/W
R/W
R
R
Bits marked as read-only must be written with "0", reading returns undefined
values.
Bit
Bit name
Function
31 to 24
HBP[7:0]
Horizontal back porch width
HBP[7:0] specifies the number of VOnCLK periods between deassertion of VOnHSYNC
and the start of active data.
The minimun value of HBP[7:0] is 2.
The actual width of the back porch is (HBP[7:0] + 1) • T
VOnCLK
,
thus spans the range (3 to 256) T
VOnCLK
23 to 16
HFP[7:0]
Horizontal front porch width
HFP[7:0] specifies the number of VOnCLK periods between the end of active data and
assertion of VOnHSYNC.
The actual width of the front porch is (HFP[7:0] + 1) • T
VOnCLK
,
thus spans the range (1 to 256) T
VOnCLK
15 to 8
HSW[7:0]
Horizontal synchronization pulse width
HSW[7:0] specifies the width of the VOnHSYNC signal in VOnCLK periods.
The minimun value of HSW[7:0] is 2.
The actual width of VOnHSYNC is (HSW[7:0] + 1) • T
VOnCLK
,
thus spans the range (3 to 256) T
VOnCLK
7 to 2
PPL[5:0]
Pixels/line
PPL[5:0] specifies the number of pixels in each line of the screen.
The actual number of pixels/line is 16 • (PPL[5:0] + 1),
thus spans the range 16 to 1024 pixels/line.
Chapter 7
Video Output
202
Preliminary User's Manual S19203EE1V3UM00
Summary of Contents for uPD72256
Page 39: ...Pin Functions Chapter 2 Preliminary User s Manual S19203EE1V3UM00 39 ...
Page 44: ...Chapter 2 Pin Functions 44 Preliminary User s Manual S19203EE1V3UM00 ...
Page 46: ...Chapter 2 Pin Functions 46 Preliminary User s Manual S19203EE1V3UM00 ...
Page 49: ...Pin Functions Chapter 2 Preliminary User s Manual S19203EE1V3UM00 49 ...
Page 52: ...Chapter 2 Pin Functions 52 Preliminary User s Manual S19203EE1V3UM00 ...
Page 54: ...Chapter 2 Pin Functions 54 Preliminary User s Manual S19203EE1V3UM00 ...
Page 331: ...External Memory Interface Controller Chapter 9 Preliminary User s Manual S19203EE1V3UM00 331 ...
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