z86131 ZiLOG Semiconductor, z86131 Datasheet - Page 33

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

ZiLOG
INTERNAL REGISTERS
Information controlling the setup and operation of the
Z86129/130/131 are maintained in several registers. The
user may read or alter the contents of these registers as re-
quired. Some registers are not available in Z86130/131 for
not supporting OSD or XDS filtering. The availability of
the internal register depends on the function of the
Z86129/130/131. This section describes all the internal reg-
ister in the Z86129/130/131.
Serial Status (SS) Register Address = Not Required
D
circuits are locked. May be used as an indication of the pres-
ence of a video signal.
D
High = Field 1.
D
in the output buffer has not been read out and new data has
been written over it.
D
than DAV is pending.
D
run.
D
Low = 1 byte, High = 2 bytes.
D
be read out.
D
is empty. Only the NOP, RESET and READ instructions
may be sent if RDY is Low.
Configuration Register Address = 00h
DS007200-TVX0199
Bit
Bit
0
1
2
3
4
5
6
7
Figure 22. ConÞguration Register (Address = 00h)
ÐLOCK.
ÐFLD.
ÐROVR.
ÐINTR.
ÐWOVR.
ÐRD2.
ÐDAV.
ÐRDY.
RDY
R
D
res
D
7
7
Signals the current video field. Low = Field 2,
Signals the number of bytes available for output.
Active High, indicating that data is available to
Active High, indicating that the port input buffer
Active High, indicating that an interrupt other
Figure 21. Serial Status Register
DAV
Active High, indicating that the internal sync
Active High, indicating that the data available
D
Active High, indicating a serial input data over-
R
D
res
6
6
(Address not required)
RD2
D
R
res
D
5
5
WOVR
D
D
res
R
4
4
INTR
R/W
VLK
D
R
D
3
3
ROVR FLD LOCK
R/W
D
HLK
R
D
2
2
MONO
D
R/W
R
D
1
1
P R E L I M I N A R Y
R/W
TVS
D
R
D
0
0
D
and Low selects NTSC. The default is NTSC. When PAL
is selected the display defaults to 15 TV scan lines per dis-
play row.
D
indicating that character luminance is output on all three
color pins (RGB). The default is Low, selecting COLOR
operation.
D
lock the VCO: Low = Internal, High = HIN. The default is
Internal.
D
tablish vertical sync lock: Low = Internal, High = V
default is Internal. When Internal lock is enabled the
V
rupts should not be selected in the Interrupt Mask register
if VLK mode is used.
D
Display Register Address = 01h
D
mode: High = DROP SHADOW and Low = BOX. The de-
fault is Low.
D
in a TEXT display: High = 15 lines/row and Low = 13
lines/row. The default is Low.
D
play: High = Disabled, Low = Enabled. The default is Low.
D
mode: High = DROP SHADOW and Low = BOX. The de-
fault is Low.
D
in a CAPTION display: High = 15 lines/row and Low = 13
lines/row. The default is Low.
D
display: High = Disabled, Low = Enabled. The default is
Low.
Bit
0
1
2
3
4
0
1
2
3
4
5
IN
ÐTVS.
ÐMONO.
ÐHLK.
ÐVLK.
ÐD
ÐTDRP.
ÐT15.
ÐTENH.
ÐCDRP.
ÐC15.
ÐCENH.
/INTRO pin defaults to the INTRO output mode. Inter-
Figure 23. Display Register (Address = 01h)
R/W
7
O15 ODRP CENH
D
Ðres.
7
Selects the number of TV lines per character row
Selects the number of TV lines per character row
Selects the television standard. High selects PAL
Selects the vertical signal source to be used to es-
Selects the horizontal signal source to be used to
Selects Drop Shadow or Full Box in TEXT
Enables Enhanced Attributes for a TEXT dis-
Selects Drop Shadow or Full Box in CAPTION
Enables Enhanced Attributes for a CAPTION
Selects monochrome operation. Active High,
R/W
Reserved.
D
6
R/W
D
5
C15
R/W
D
4
CDRP TENH
R/W
D
NTSC Line 21 Decoder
3
R/W
D
2
Z86129/130/131
R/W
T15
D
1
IN
TDRP
R/W
. The
D
0
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