
FUNCTIONAL DESCRIPTION
(continued)
IV - I
2
C Bus Register Map
(continued)
IV.1 - Registers Functions
(continued)
Register
Function
Bit(s)
Description
R7
Address
07H
Display mode
BOX ON 0, 1-23,24
(D0, D1, D2)
TOP / BOTTOM
Single/ Double Height
(D4/D3)
Conceal / Reveal (D5) Conceal Reveal Function
Cursor ON/OFF (D6)
Cursor position given by row/column value of R9/R10
STATUS ROW
BTM / TOP (D7)
0-23) or after (D7 = 0).
VPS Enable (D4)
D4 = 1 Enable VPS acquisition and DV signal output.
Clear Memory (D3)
D4 = 1 Clear memory.
Chapter selected with A2A1A0 (D2, D1, D0) R4.
Chapter Address
(D2, D1, D0)
The "boxing" function is enabled on row 0,1-23 and 24 by
D0, D1 and D2 set to one.
X0 = Normal
01 = double height Rows 0 to 11
11 = double height Rows 12 to 23
The row 24 is displayed before the "Main text Area" (lines
R8
Memory access
Chapter selection
R9 to R11A
Address
08H to 0BH*
Active row address (R9), active column address (R10).
Data contained in R11A read (written) from (to) memory by microprocessor via I
2
C.
R11B
Address
0BH*
Status
VCS QUAL (D0)
Good VCS quality signal detected (D0 = 1).
Bad VCS quality signal detected (D0 = 0).
Good TELETEXT signal (D1 = 1).
Bad TELETEXT signal (D1 = 0).
If D1 = 0 frame frequency is 50Hz (only valid with good
VCS)
DATA QUAL (D1)
50/60Hz (D7)
* Reading of R11A or R11B is determined by register 0, bit D0. However, write operation is always performed on R11A register.
5
START
COLUMN
0
1
2
3
4
5
6
PRD4
PRD3
PRD2
PRD1
PRD0
Do care magazine
Do care page tens
Do care page units
Do care hours tens
Do care hours units
Do care minutes tens
Do care minutes units
HOLD
PT3
PU3
X
HU3
X
MU3
MAG2
PT2
PU2
X
HU2
MT2
MU2
MAG1
PT1
PU1
HT1
HU1
MT1
MU1
MAG0
PT0
PU0
HT0
HU0
MT0
MU0
The abbreviations have the same significance as in Table 1 with the exception of the "DO CARE" entries. It is only when this bit is "1"
that the corresponding digit is taken into consideration on page request. For example, a page defined as "normal" or one defined as
"timed" may be selected.
If "HOLD" is low the page is held. The addressing of successive bytes via the I
2
C is automatic.
5
Table 4 :
Register R3
V - Character Sets
The complete character set with 8-bit decoding is
given in Table 5.
Characters in columns 0 and 1 are normally dis-
played as blanks. Black dots represent the charac-
ter shape whereas white dots represent the
background.
Each character can be identified by a pair of corre-
sponding row and column integers : for example
the character "3" may be indicated by 3/3.
A rectangle may be represented as follows :
The characters 8/6, 8/7, 9/5, 9/7 are used as spe-
cial characters, always in conjunction with 8/5.
The 13 national characters are placed in columns
with bit 8 = 0.
STV5348 - STV5348/H - STV5348/T
11/22