Datasheet

TFP410-EP
PanelBus™ DIGITAL TRANSMITTER
SGLS344A − JULY 2006 − REVISED MAY 2011
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
data deskew feature
The deskew feature allows adjustment of the input setup/hold time. Specifically, the input data DATA[23:0] can
be latched slightly before or after the latching edge of the clock IDCK± depending on the amount of deskew
desired. When deskew enable (DKEN) is enabled, the amount of deskew is programmable by setting the three
bits DK[3:1]. When disabled, a default deskew setting is used. To allow maximum flexibility and ease of use,
DKEN and DK[3:1] are accessed directly through configuration pins when I
2
C is disabled, or through registers
of the same name when I
2
C is enabled. When using I
2
C mode, DKEN should be tied to ground to avoid a floating
input.
The input setup/hold time can be varied with respect to the input clock by an amount t
(CD)
given by the formula:
t
(CD)
= (DK[3:1] – 4) × t
(STEP)
Where:
t
(STEP)
= Adjustment increment amount
DK[3:1] = Number from 0 to 7 represented as a 3-bit binary number
t
(CD)
= Cumulative deskew amount
(DK[3:1] – 4) is simply a multiplier in the range {–4, –3, –2, –1, 0, 1, 2, 3} for t
(STEP)
. Therefore, data can be
latched in increments from four times the value of t
(STEP)
before the latching edge of the clock to three times
the value of t
(STEP)
after the latching edge. Note that the input clock is not changed, only the time when data
is latched with respect to the clock.
−t
(CD)
000
−4 × t
(STEP)
100
0
Default Falling
111
3 × t
(STEP)
000
−4 × t
(STEP)
100
0
Default Rising
111
3 × t
(STEP)
DATA[23:0]
IDCK±
DK[3:1]
t
(CD)
t
(CD)
−t
(CD)
t
(CD)
Figure 8. A Graphical Representation of the De-Skew Function
hot plug/unplug (auto connect/disconnect detection)
The TFP410 supports hot plug/unplug (auto connect/disconnect detection) for the DVI link. The receiver sense
(RSEN) input bit indicates if a DVI receiver is connected to TXC+ and TXC–. The HTPLG bit reflects the current
state of the HTPLG pin connected to the monitor via the DVI connector. When I
2
C is disabled (ISEL = 0), the
RSEN value is available on the MSEN pin. When I
2
C is enabled, the connection status of the DVI link and
HTPLG sense pins are provided by the CTL_2_MODE register. The MSEL bits of the CTL_2_MODE register
can be used to program the MSEN to output the HTPLG value, the RSEN value, an interrupt, or be disabled.
The source of the interrupt event is selected by TSEL in the CTL_2_MODE register. An interrupt is generated
by a change in status of the selected signal. The interrupt status is indicated in the MDI bit of CTL_2_MODE
and can be output via the MSEN pin. The interrupt continues to be asserted until a 1 is written to the MDI bit,
resetting the bit back to 0. Writing 0 to the MDI bit has no effect.