z86131 ZiLOG Semiconductor, z86131 Datasheet - Page 53

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

ZiLOG
DEMONSTRATION PROGRAMS
Communicating with the Z86129/130/131
Communications with the Z86129/130/131 is accom-
plished using its serial communications interface. Through
hardware setup, this interface can be configured into either
of two serial protocols, I
setup have been provided in the Serial Communications In-
terface section, page 24, and are not covered here. It is as-
sumed that the user is familiar with the serial protocol re-
quirements.
Note: In the following descriptions <ENTER> means press the
I
The Z86129/130/131 is configurable as an I
The PC communicates with the Z86129/130/131 through
its parallel port. These programs are not intended as exam-
ples of how to program the application but are only provided
as a means of illustrating the serial control process and the
capability of the Z86129/130/131.
The three programs available are titled IICO, SCRIPTI and
XDSCAP. These programs have been compiled and run sat-
isfactorily with the Z86129/130/131 in a test board. Com-
piled versions are available on disk. Contact your local
ZiLOG sales office for further information on these pro-
grams.
IICO Program
This program sends one byte to the Z86129/130/131 with-
out checking the status of the READY bit. The program re-
turns the contents of the Serial Status (SS) Register after the
command has been entered. When the program is active the
screen displays:
The user may enter any valid one byte command such as
FBh (Reset) or 00h (NOP) and then hit the ENTER key. The
screen then displays the byte entered and the SS register
contents as follows:
This example presents that the NOP command was entered.
The SS register contents, 83h, indicates that the RDY, FLD
and LOCK bits are High indicating that the serial port is
ready for further input, that the input video signal was in
DS007200-TVX0199
2
C Operation
IIC Command Byte >
IIC Byte = 00
IIC Status = 83h
Enter key. An asterisk (*) signifies that everything fol-
lowing the asterisk in that line is a comment.
2
C or SPI. The details of hardware
2
C slave device.
P R E L I M I N A R Y
Field 1 at the time the status was read and that the part is
operating in video lock mode.
The IICO program is exited by entering a Control+C (^C)
character.
For example, entering the following single byte commands
would:
The commands that control most of the display capability
of the Z86129 are all one byte commands which can be en-
tered using the IICO program. These commands are tabu-
lated below for convenience.
General Commands
Caption/Text Display Mode Commands
(Z86129 only)
CPTX = 10hÐ1Fh.
mands. These commands select the desired Line 21 data
stream (Closed Caption or Text) for display. See the Com-
mands section, page 29, for a complete description of the
CPTX Display Mode command.
Caption and Text display commands are one byte com-
mands. A data channel can be selected for display with the
display either enabled (DEC ON) or disabled (DEC OFF).
All these commands turn off an active XDS display mode.
The following table summarizes the device’s Caption and
Reset the part
Set the part to CC1 display mode,
decoder ON(Z86129 only).
Change to the XDS Graze display mode,
16 Second Timer ON(Z86129 only).
Return to the CC1 display mode,
decoder ON(Z86129 only).
Serial Command
RESET
NOP
SSB
Bit
R/W
CM7 CM6
0
Figure 39. CPTXÐCaption/Text Display
R/W
0
CM5
R/W
Caption and Text display mode com-
(CPTX = 10hÐ1Fh)
0
CM4
R/W
1
Command Code
FBh, FCh, 00h
00h
FFh,...FFh,FEh
CM3
R/W
FLD
NTSC Line 21 Decoder
LANG CPTX DONOF
CM2
R/W
Z86129/130/131
CM1
FB, FC, 00
17h
23h
17h
R/W
CM0
R/W
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