z86131 ZiLOG Semiconductor, z86131 Datasheet - Page 29

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

ZiLOG
COMMANDS
Serial Port Commands
The majority of the Z86129/130/131 commands are com-
mon to both the I
commands must be contained within the Start—Slave Ad-
dress sequence. Text or Caption display commands are
available only in Z86129.
Note: In the following Command descriptions, the letter 'h' fol-
Reset
RESET = FBh, FCh, 00h.
sequence in SPI or I
lishes all the specified default settings in the device, but it
does not reset the serial port itself. This sequence can be en-
tered without RDY being set.
No Operation
NOP = 00h.
I
the RDY bit in the Serial Status (SS) register and can be
executed independent of the RDY status.
Serial Sync Bytes
SSB = FFh,....,FFh,FEh.
mode only. This command actually consists of a string of
single-byte commands in the form FFh,....FFh,FEh. SPI
mode communications can be synchronized by sending a
synchronizing data string to the part. This string should con-
sist of at least two SSB bytes of FFh followed by one SSB
byte of FEh. At the end of the FEh byte the port is ready
for use.
DS007200-TVX0199
Serial Command
RESET
NOP
SSB
2
C mode. The NOP command does not affect the status of
lowing a command code designates Hexadecimal nota-
tion.
Table 17. Basic Serial Commands
NOP is a one-byte command for use in SPI or
2
C and SPI modes. In the I
2
C mode. The RESET command estab-
Command Code
FBh, FCh, 00h
00h
FFh,...FFh,FEh
Serial Sync Bytes are used in SPI
RESET is a three byte command
Note
SPI or I
SPI or I
SPI mode only
2
C mode, the
2
2
P R E L I M I N A R Y
C
C
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.
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.
Table 18 summarizes the device’s Caption and Text display
modes and the proper command code to activate them:
XDS Display Mode and 16 Second Erase Timer
Commands (Z86129 Only)
XDS DISP = 20hÐ27h.
byte commands. These commands control the selection of
XDS display modes and the state of the 16 Second Erase
Timer. The 16 Second Erase Timer is active only for Cap-
tion and XDS display modes. The 16 Second Erase Timer
has no affect on TEXT mode displays.
Bit
CPTX Command
CC1
CC2
CC3
CC4
T1
T2
T3
T4
CM7
R/W
0
Table 18. Caption and Display Commands
Figure 15. CPTXÐCaption/Text Display
CM6
R/W
0
CM5
R/W
Caption and Text display mode com-
(CPTX = 10hÐ1Fh)
0
Decoder ON
XDS Display commands are one
CM4
R/W
1
CPTX Command Code
1Dh
1Bh
17h
15h
1Fh
13h
19h
11h
CM3
R/W
FLD
NTSC Line 21 Decoder
LANG CPTX DONOF
CM2
R/W
Z86129/130/131
Decoder OFF
CM1
R/W
1Eh
1Ch
16h
14h
12h
10h
1A
18
CM0
R/W
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