Z86130 ZILOG [Zilog, Inc.], Z86130 Datasheet - Page 24

• Manufacturer Part Number: Z86130
• Description: NTSC LINE 21 DECIDER
• Manufacturer: ZILOG [Zilog, Inc.]

Z86129/130/131
NTSC Line 21 Decoder
COMMANDS (Continued)
Caption and Text display modes and the proper command
code to activate them:
XDS Display Mode and 16 Second Erase Timer
Commands
XDS DISP = 20h-27h. XDS Display commands are one
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
Caption and XDS display modes. The 16 Second Erase
Timer has no affect on TEXT mode displays
Note: Changing the ON/OFF state of the 16 Second Erase
Timer has no affect on the current display mode in operation.
Read And Write Commands
Read Selects. There are two Read Select commands
(RDS1 and RDS2) in the Z86129/130/131. Each
command is one byte in size and indicates that a read
should take place. RDS1 specifies that one byte will be
read from the Z86129/130/131. Likewise, RDS2 indicates
that two bytes will be read.
24
16 Second Erase
XDS Display
Command
Command
XDSG
CPTX
XDSF
Timer
Table 9. Caption and Display Commands
CC1
CC2
CC3
CC4
T1
T2
T3
T4
Table 10. XDS Display Commands
16 Sec Tmr ON
Decoder ON
XDS Display Command Code
CPTX Command Code
1Dh
1Fh
1Bh
17h
15h
13h
11h
19h
23h
21h
20h
16 Sec Tmr OFF
Decoder OFF
1Ch
1Eh
16h
14h
12h
10h
27h
25h
24h
1A
18
P R E L I M I N A R Y
RDS1 = 40h-47h. RDS1 is a one-byte command used to
initiate a one-byte read sequence by moving the contents
of the register identified by the address field (AD00:02) of
the command to the output register. Addresses 0h-7h are
valid in the RDS1 command field AD00:02.
RDS2 = 60h-66h. RDS2 is a one byte command which is
used to initiate a two byte read sequence by moving the
contents of the two consecutive registers, starting with the
one identified by the address portion of the command
(AD00:AD02), to the output registers and setting the RD2
bit in the SS register. Only Addresses 0h-6h are valid in the
RDS2 command field AD00:02.
Note: For XDS data recovery, when the XDS Filter
Register (see Internal Register section) is enabled for the
desired packets, the Z86129/130/131 will automatically
establish the two byte recovery mode and move the
recovered data bytes to the output register.
Bit
Bit
Figure 14. RSD2-Read Two Bytes (RDS2 = 60h-66h)
Figure 13. RDS1-Read One Byte (RDS1 = 40h-47h)
CM7
W
W
7
0
0
CM6
W
1
1
W
6
CM5
W
5
1
0
W
CM4
4
W
0
0
W
CM3 CM2 CM1
W
3
W
0
0
AD02 AD01 AD00
AD02 AD01 AD00
W
2
W
DS96TEL0200
1
W
W
CM0
0
W
W