83C055 Philips Semiconductors, 83C055 Datasheet - Page 21

• Manufacturer Part Number: 83C055
• Description: Microcontrollers for TV and video MTV
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Notes to the description of OSAT bits
1. The latches in which the E,SR, D, and Sh bits are captured are cleared to zero at the start of each vertical scan. This
2. For SplitBSpace, a change in B and Bcolor occurs halfway through the character horizontally.
3. The normal Space character has no effect on the Bcolor value.
4. The Bcolor value is not cleared between vertical scans, so that if a single background colour is all that is needed in
Table 22 OSD outputs related to character bit map value, Fcolor, Bcolor and B bits
Notes
1. Bcolor (BC2,BC1,BC0) values ‘000’ and ‘111’ minimize the occurrence of transient states among the VID2 to VID0
2. The background colour defined by the most recently encountered BSpace or SplitBSpace character is maintained
1996 Mar 22
CHARACTER BIT MAP VALUE
Microcontrollers for TV and video (MTV)
means that if the first text line on the screen is a short row, or if it contains either double size or shadowing, the text
must be preceded by a New Line character. Like all such characters, this initial New Line advances the vertical
screen position; the VStart value (see register OSORG; Section 13.9) should take this fact into account.
an application, it can be set via a single BSpace character during program initialization, and never changed
thereafter. In order for such a BSpace to actually affect the 83C055 internal Bcolor register the Mode field of the
OSMOD register must be set to ‘01B’ (or higher) so that the OSD hardware is operating (see register OSMOD;
Section 13.8).
outputs.
on the VID2 to VID0 pins except at the following times:
a) During the active time of HSYNC.
b) During the active time of VSYNC.
c) During those pixels of an active character that correspond to a logic 1 in the character’s bit map.
d) During a ‘shadow’ bit.
logic 1
logic 0
VID2
BC2
FC2
21
OSD OUTPUTS (notes 1 and 2)
VID1
FC1
BC1
VID0
BC0
FC0
83C145; 83C845
83C055; 87C055
Product specification
driven active
VCTRL
B