z86131 ZiLOG Semiconductor, z86131 Datasheet - Page 56

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

Z86129/130/131
NTSC Line 21 Decoder
DEMONSTRATION PROGRAMS (Continued)
viding the interrupt output signal. There is no INTRO output
in the Z86130 for PB output.
The interrupt status can be polled through bit D 3 of the Se-
rial Status (SS) Register if the interrupt signal cannot be
used.
Interrupts are disabled when the Interrupt Mask Register
has been set to all zeros. Conversely, interrupts are enabled
by setting one or more of the active bits to a one. When en-
abled, the INTRO signal becomes a one when the enabled
mask event(s) becomes active. If more than one event has
been activated, the Interrupt Request Register must be que-
ried to determine which event has occurred. The DLE and
EOF interrupts are cleared at the end of the field in which
they occurred.
Interrupt Mask Register Script Files
SPI Operation
The serial port of the Z86129/130/131 may be configured
to operate as an I
always acts as the slave device with the master generating
the required clock and input data signals. Two C language
programs available from ZiLOG enable a PC to perform as
the I
municates with the Z86129/130/131 through it's parallel
port. These programs are not intended as examples of how
to program the application but are only provided as a means
of illustrating the serial control process.
The two programs available, SEROUT and SCRIPT are the
SPI equivalent to the I
spectively.
SEROUT 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:
SPI Command Byte
The user may enter any valid one byte command such as
00h (NOP) and then hit the ENTER key. The screen then
56
File Name
INTRD
INTRLK
INTRX
INTRC
2
C or SPI master device of an application. The PC com-
COMMAND
{xxh,yyh}
{c7,02}
{c7,08}
{c7,20}
{c7,12}
2
C or SPI interface. The Z86129/130/131
2
C programs IICO and SCRIPTI, re-
Comments
*set DLE active
*set dLOK active
*set dXDS active
*set DLE & dC/T active
P R E L I M I N A R Y
displays the byte entered and the SS register contents as fol-
lows:
This example shows that the NOP command was entered.
The SS register contents, 83h, indicates that the RDY, FLD
and LOCK bits are “ones” indicating that the serial port is
ready for further input, that the input video signal was in
Field 1 at the time the status was read and that the part is
operating in video lock mode.
When this program is used, a modified version of the RE-
SET can only be used. It is entered as two, one-byte com-
mands; FBh and 00h.
The SEROUT program is exited by entering a Control C
(^C) character.
Script Program
This program is designed to send any number of one or two-
byte commands to the Z86129/130/131. The list of com-
mands to be executed are contained in Script files that have
the extension
sion, SCRIPTI, can be used with this program.
The program is invoked by typing:
Note: File_name without the .SER extension.
The screen displays:
When all the commands in the file have been successfully
sent to the Z86129/130/131, the PC returns to the system
prompt.
The program checks the RDY status before sending each
byte. If, during the entry of a command, the RDY bit is not
found to be a “one”, the program reports the contents of the
SS register and then continues checking for RDY.
Programs only for the Z86130
The Z86130 is designed specifically for the V-Chip appli-
cations. Most of the demo programs can be run as described,
but the Z86130 must have its own demo programs, includ-
ing the demo programs described in the previous section for
accessing the program-blocking specific registers in it. For
SPI Byte = 00
SPI Return Val = 83h
SI File_name<ENTER>
EEG CCD2 Serial Interface Script Player
Version x.xx
Script File Done
.SER
. The Script files used with the I
DS007200-TVX0199
ZiLOG
2
C ver-