
1999 Oct 27
23
Philips Semiconductors
Preliminary specication
Standard TV microcontrollers with
On-Screen Display (OSD)
SAA55xx
M1 to M0
mode control bits timer/counter 0; M<1:0>:
00 = 8-bit timer or 8-bit counter with divide-by-32 prescaler
01 = 16-bit time interval or event counter
10 = 8-bit time interval or event counter with automatic reload upon overflow;
reload value stored in TH0
11 = one 8-bit time interval or event counter and one 8-bit time interval counter
Text Register 0 (TXT0)
X24 POSN
store packet 24 in extension packet memory (logic 0) or page memory (logic 1)
DISPLAY X24
display X24 from page memory (logic 0) or extension packet memory (logic 1)
AUTO FRAME
FRAME output switched off automatically if any video displayed (logic 1)
DISABLE HEADER ROLL
disable writing of rolling headers and time into memory (logic 1)
DISPLAY STATUS ROW ONLY
display row 24 only (logic 1)
DISABLE FRAME
FRAME output always LOW (logic 1)
VPS ON
enable capture of VPS data (logic 1)
INV ON
enable capture of inventory page in block 8 (logic 1)
Text Register 1 (TXT1)
EXT PKT OFF
disable acquisition of extension packets (logic 1)
8-BIT
disable checking of packets 0 to 24 written into memory (logic 1)
ACQ OFF
disable writing of data into Display memory (logic 1)
X26 OFF
disable automatic processing of X/26 data (logic 1)
FULL FIELD
acquire data on any TV line (logic 1)
FIELD POLARITY
VSYNC pulse in second half of line during even eld (logic 1)
H POLARITY
HSYNC reference edge is negative going (logic 1)
V POLARITY
VSYNC reference edge is negative going (logic 1)
Text Register 2 (TXT2)
ACQ BANK
select acquisition Bank 1 (logic 1)
REQ3 to REQ0
page request
SC2 to SC0
start column of page request
Text Register 3 (TXT3)
PRD4 to PRD0
page request data
Text Register 4 (TXT4)
OSD BANK ENABLE
alternate OSD location available via graphic attribute, additional 32 locations
(logic 1)
QUAD WIDTH ENABLE
enable display of quadruple width characters (logic 1)
EAST/WEST
eastern language selection of character codes A0H to FFH (logic 1)
DISABLE DOUBLE HEIGHT
disable normal decoding of double height characters (logic 1)
B MESH ENABLE
enable meshing of black background (logic 1)
C MESH ENABLE
enable meshing of coloured background (logic 1)
TRANS ENABLE
display black background as video (logic 1)
SHADOW ENABLE
display shadow/fringe (default SE black) (logic 1)
BIT
FUNCTION