
ICS2008A
6
The SMPTE Status Register is a read only register which
contains video and LTC status.
FRAMEIN This bit indicates the state of the FRAME
input pin. It is used as an alternate source for B/A frame
status. This is useful when the quality of the video signal is
not good enough to extract the B/A frame status.
CLICK This bit indicates the state of the CLICK input
pin. It can be used as a synchronization source for the LTC
transmitter.
LTCLOCK When a valid forward or backward LTC sync
pattern is detected, this bit is set to one. It is reset to zero when
an expected LTC sync pattern is missed or an invalid LTC bit
is detected.
CODEDIR The code direction bit works in conjunction
with the LTCLOCK bit. When the LTCLOCK bit is set to one,
the CODEDIR bit is valid. Otherwise, it is not. See the table
below.
VLOCK This is a hardware driven bit which indicates that
genlock has been achieved with the selected video SYNC
source.
FRAME & FIELD The hardware SYNC separator detects
the field and frame from the selected video input. The even/
odd fields are identified by a 1/0 in bit 6. Bit 7, FRAME, is
valid for PAL video after line 6. Bit 6, FIELD, is valid after
line 5 in NTSC mode or line 2 in PAL mode.
The SMPTE2 register is the register which points to the 57
indirect registers. When reading or writing an indirect
register, the value in the ADDRESS pointer, SMPTE2 bits 5
to 0, is the address of the register accessed through SMPTE3.
If the AUTOINC bit is set to one, at the end of an access cycle
to SMPTE3, ADDRESS will automatically increment.
Otherwise, ADDRESS holds its value.
SMPTE3 is the data register through which all of the indirect
registers are accessed. The address for a given register must
first be set in SMPTE2 before accessing that register.
Indirect Registers
The following describes the functions controlled by the
indirect registers. A map of the indirect registers follows this
section, on page 11.
LTC Read Registers IR0-IR7 (read-only)
These read only registers contain the LTC data as received.
Both forward and backward frames are stored with LTC bit 0
in the LSB of IR0 and LTC bit 63 in the MSB of IR7.
LTC Write Registers IR8-IRF
These registers contain the data to be sent by the LTC trans-
mitter. The LSB of IR8 is sent as LTC bit 0, and the MSB of
IRF is sent as LTC bit 63. The data is transmitted as it is stored
in IR8-IRF.
LTCLOCK CODEDIR
LTC RECEIVER STATUS
0
X
Looking for SYNC pattern
1
0
Receiving LTC (FORWARD)
1
Receiving LTC (BACKWARD)
SMPTE Status Register
FRAMEIN (input = 1-high, 0-low)
CLICK (input = 1-high, 0-low)
LTCLOCK (1-locked, 0-not locked)
CODEDIR (1-bkwd, 0-fwd)
Reserved
VLOCK (1-locked, 0-not locked)
FIELD
FRAME (PAL only)
7
6
5
4
3
2
1
0
SMPTE1
Indirect Address Register
ADDRESS
Reserved
AUTOINC (1-increment, 0-hold)
SMPTE2
7
6
5
4
3
2
1
0
Indirect Address Register
SMPTE3
7
6
5
4
3
2
1
0