z86131 ZiLOG Semiconductor, z86131 Datasheet - Page 51

• Manufacturer Part Number: z86131
• Description: Ntsc Line 21 Decoder
• Manufacturer: ZiLOG Semiconductor

ZiLOG
POPSET screens are created in off-screen memory while
the previous screen is displaying. Up to 8 rows of characters
can be defined. These rows can be mapped to any of 15 dis-
play rows using the POP ROW SEL command. Double-
High rows may also be defined with POP ROW SEL. The
FLIP command is then used to “pop-on” up to 8 rows of
characters replacing the previous screen. The off-screen
rows may be mapped to the same row numbers as the on-
screen rows.
In some applications it may be necessary to access the dis-
play hardware at a lower level to achieve special screen ef-
fects. Examples of these special situations include the fol-
lowing:
1. More than 8 on-screen rows required in a “pop-on”
2. Characters must be added dynamically to an on-screen
3. On-screen rows must be dynamically moved, disabled
The Z86129 supports manual screen mapping and display
control commands to handle these special applications.
These commands allow each of the 16 physical rows of
character memory implemented in the device to be mapped
to any of 15 display row positions.
Additionally the 16 physical rows can be set for single or
double height and independently enabled and disabled.
Manual row mapping and control commands should only
be used in the POPSET OSD mode.
The procedure for manual row control is as follows:
1. Use the POPSET command to select the OSD pop-up
2. Select a physical row (0 through 15) using the PHY
3. Use the WRITE MAP command to set the display row
The CURSOR SET, WRITE CHAR and WRITE CHARD
commands are used to position the cursor and write the char-
acters in the selected physical row.
A physical row may be re-selected at any time to change
its characters, row maps, Double-High mode or enable sta-
tus. For example, it may be desirable to load several rows
of characters into physical memory without enabling them.
DS007200-TVX0199
style screen.
display.
or enabled.
mode. This command prepares the Z86129 for OSD
input, clears the row maps and erases character mem-
ory.
ROW SEL command.
(1 through 15), Double-High bit, and enable bit of the
selected physical row.
P R E L I M I N A R Y
All of the rows could then be made to “pop” onto the screen
immediately by setting their enable bits.
The following example uses manual row mapping and con-
trol to write three rows of characters. The first row is a Dou-
ble-High row that is enabled before the characters are sent,
thereby allowing the characters to “paint” onto the screen
as they are received. The second and third row are not ini-
tially mapped or enabled when the characters are written.
They are then mapped and enabled after a two second pause.
A new row is then created off-screen to replace the third
row. Finally, after a 2 second pause the second row is moved
to a new display row, the original third row is disabled and
the new third row is mapped and enabled.
OSD
Command
{33}
{A1,00}
{A4,31}
{A2,02}
{A3,02}
{A1,01}
{A2,00}
{A3,0a}
'ÔThese two rows areÕ
{A1,07}
{A2,00}
{A3,06}
'Ôenabled after a pauseÕ
{A6,40}
{A1,01}
{A4,16}
{A1,07}
{A4,17}
Function
*select POPSET mode
*select physical row 0
*map it to display row 1, enable, double
*cursor to 1
*green
*Double-Wide text
*ÒThe First RowÓ
*select physical row 1
*cursor to 0
*yellow
*single wide text
*select prow 7
*cursor to 0
*cyan
*Single wide text
*wait 2 seconds
*do the map and enable
*select physical row 1
{A4,16}
*map it to display row 6, enable
*select prow 7
*map it to drow 7, enable
*prepare a new row to replace row 7
NTSC Line 21 Decoder
Z86129/130/131
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