LM1238AAD/NA NOPB National Semiconductor, LM1238AAD/NA NOPB Datasheet - Page 23

• Manufacturer Part Number: LM1238AAD/NA NOPB
• Manufacturer: National Semiconductor

Specifications of LM1238AAD/NA NOPB

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Package Type: MDIP
• Lead Free Status / RoHS Status: Compliant

Control Register Definitions
Global Video Control Register (I
Register Name (address): GLOBALCTRL (0x0819h)
Bit 0
Bit 1
Bits 7–2 Die ID. These bits are read only masked so that they can be assigned a value to differentiate between masked dies and
PLL Range Register (I
Register Name (address): CLMP/PLL/VBL/OOR (0x081Eh)
Bits 1–0 PLL Frequency Range Control. These bits assist the PLL in locking to the desired pixel frequency. They are set based
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Software Reset and Test Control Register (I
Register Name (address): SRTSTCTRL (0x081Fh)
Bit 0
Bits 1–7 Reserved.
Blank Video. When this bit is a one, blank the video output. When this bit is a zero allow normal video out. This register
bit is OR’d with the other video blank signals, both active and static, and sent to the preamplifier as BLANK_OUT.
Power Save. When this bit is a one, shut down the analog circuits to support sleep mode. When this bit is a zero
(default) enable the analog circuits for normal operation. This register bit is fed to the preamplifier interface as
PWR_SAVE so that the amplifier can be put in to low power sleep mode. It is also OR’d with the blanking signals to
blank the video.
die revisions.
upon the nominal desired horizontal frequency range as per the PLL section. These bits, PFR0,1 are presented at the
PLL interface as the signals ‘Free_run_freq0’, and ‘Free_run_freq1’.
Vertical Blank Disable. When this bit is set to 0, the internally generated vertical blanking pulse is OR’d with the
horizontal blank pulse internal to the logic core, to blank the video during retrace. When this bit is set to 1 (default) the
internal vertical blanking is disabled.
OSD Override. When this bit is 0 (default) normal video operation is assumed. When this bit is 1, the OSD select is
overridden, and OSD only is selected, preventing normal video from being displayed (used for ‘out-of-range’ condition).
Free Run Enable. When this bit is set to 0 (default), the PLL will be supplied with the H flyback synchronization pulse.
When set to 1, the H flyback pulse will be gated off.
Clamp Polarity. Determines the polarity of the clamp signal used by the LM1238. When this bit is 0 (default) the LM1238
requires a positive clamp signal. When this bit is 1, the LM1238 requires a negative going clamp signal.
Burn-in Screen Enable (BIS). When this bit is a ’1’, the burn-in screen is active and input video will be ignored. When
this bit is a ’0’ (default), the burn-in screen is disabled.
Interface. When this bit is set to 1, the jitter reduction circuit is set to alternate the phase every alternate field. When it
is set to 0 (default), normal progressive scan is assumed.
Software Reset. Setting this bit causes a software reset. All registers (except this one) are loaded with their default
values. All operations currently in progress are aborted (except for I
when the reset has been completed.
D_ID5
RSV
INT
7
7
7
2
C address 0x081Eh)
D_ID4
RSV
BIS
6
6
6
2
C address 0x0819h)
D_ID3
CLMP
RSV
5
5
5
2
C address 0x081Fh)
(Continued)
D_ID2
RSV
FRE
4
4
4
23
D_ID1
OOR
RSV
3
3
3
2
D_ID0
C transactions). This bit automatically clears itself
RSV
VBL
2
2
2
PFR1
RSV
PS
1
1
1
SRST
PFR0
BV
0
0
0
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