ST92185B STMicroelectronics, ST92185B Datasheet - Page 127

• Manufacturer Part Number: ST92185B
• Description: 16k/24k/32k Rom Hcmos Mcu With On-screen-display
• Manufacturer: STMicroelectronics

ON SCREEN DISPLAY (Cont’d)
SCROLLING
(SCHR)
R249 - Read/Write
Register Page: 32
Reset Value: 0000 0000b (00h)
Bit 7 = DH: Global Double Height control bit .
This bit must only be used in Page Mode. When
DH is set, the display is turned in double height in-
cluding the header, excluding the vertical offset
before the display area. The status rows are not
affected by the DH bit and they remain in normal
height. Depending on the value of the UP/D con-
trol bit, when DH is set, the first or second half of
the page is displayed in double height. This bit as-
sumes a zooming function.
Notes:
– In global double height, when the top half page
– When the bottom half page is displayed, if row 23
is displayed, if row 11 has a double height at-
tribute, the first status row is corrupted. To avoid
this effect, save row 11, remove the serial double
height attribute from this row and display the up-
per part of the page. Then, before displaying the
lower part of the page, restore the serial DH at-
tribute in row 11.
has a double height attribute, the first status row
is not displayed. To avoid this effect remove the
serial double height attribute from row 23.
DH
7
EER
UP/D
CONTROL
LRS4
LRS3
HIGH
LRS2
REGISTER
LRS1
LRS0
0
Bit 6 = EER: End of Extra Row flag bit.
This bit is forced to "1" by hardware when the last
line of the extra row is displayed in case of scroll-
ing in normal height. This bit is Read only.
In Global double height, the EER bit is set to "1"
each time the last line of a new displayed row ap-
pears.
Bit 5 = UP/D: Scrolling Up/Down
This bit has two functions: to control the scrolling
direction and to select the half part of the page in
Global Double Height display.
Scrolling direction:
0: Top-Down shift
1: Bottom-up shift
Half-page selection:
When DH is set, if UP/D is set, the upper half of the
page is displayed (i.e. Header and the page rows 1
to 11).
When DH is set, if UP/D is reset, the lower half of
the page is displayed (i.e. rows 12 to 23 and the
Status rows).
The UP/D control bit must be defined before set-
ting the Global height (DH bit); changing UP/D af-
ter DH is set, will not change the already selected
half page.
Bit 4:0 = LRS[4:0]: Last row to be scrolled (1 to
23). In case of scrolling in global double height, the
Last row must be equal to 0x 10111 to display the
status row in the two half pages.
ST92185B - ON SCREEN DISPLAY (OSD)
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