Peritek
5-42
Programming On-board Devices and Memories
Table 5-24 VCD-V /MF Zoom Control Register (BT482 Analog and
Digital)
Bit
Mnemonic
Function
31-8
spare
not used, not defined, reads 0 or 1
5-7
CR0-CR2
Zoom control bits 0-2
CR2
CR1
CR0
Zoom Factor
0
0
0
16
0
0
1
8
0
1
0
7
0
1
1
6
1
0
0
5
1
0
1
4
1
1
0
3
1
1
1
1
4
BP
Back porch adjust
3
FP
Front porch adjust
BP
FP Function
x
0
Horizontal Front Porch is not
delayed
x
1
Horizontal Front Porch is delayed
0
x
Horizontal Back Porch is not delayed
1
x
Horizontal Back Porch is delayed
It is not necessary to provide more than 1 bit for
FB and BP because VCLK is in increments of 2
pixel clocks. Additional changes can be made
directly to the HSBLNK and HESYNC.
2
SM
Sync mode. Affects Sync on VGA connector.
SM = 0
selects
Composite Sync
. Horizontal
serrations are present during Vertical Sync.
SM = 1
selects
Block Sync
. Horizontal
serrations are absent during Vertical Sync.
1
INTER
Set
to provide field sync to BT482 during
interlaced operation. Must be
clear
for non-
interlaced operation. You also have to set or
clear Bit 4 in the BT482 cursor register.
0
SETUP
Works only when INTER is clear
.
Set
to
select 7.5 IRE level blanking step.
Clear
for no
blanking step. BT482 Command Register B bit
5 controls step in interlaced mode.
Summary of Contents for VCD-V
Page 2: ...Peritek ...
Page 3: ...Peritek ...
Page 5: ...Peritek ...
Page 6: ...Peritek ...
Page 10: ...Peritek ...
Page 42: ...Peritek Installing Your Peritek Graphics Board 2 11 Figure 2 3 Jumper Locations for the VCD V ...
Page 94: ...Peritek Theory of Operation 4 15 Figure 4 1 VCD V Block Diagram ...
Page 95: ...Peritek 4 16 Theory of Operation Figure 4 2 VCU V Block Diagram ...
Page 96: ...Peritek Theory of Operation 4 17 Figure 4 3 VCT V Block Diagram ...