Datasheet

Table Of Contents
ADV7188
Rev. A | Page 78 of 112
Interrupt Request Output Operation
When an interrupt event occurs, the interrupt pin
INTRQ
goes low, with a programmable duration given
by INTRQ_DUR_SEL [1:0]
INTRQ_DUR_SEL [1:0], Interrupt Duration Select,
Address 0x40 [7:6], User Sub Map
Table 98. INTRQ_DUR_SEL [1:0] Function
INTRQ_DUR_SEL [1:0] Description
00 (default) 3 XTAL periods
01 15 XTAL periods
10 63 XTAL periods
11 Active until cleared
When the active-until-cleared interrupt duration is selected and the
event that caused the interrupt is no longer in force, the interrupt
persists until it is masked or cleared.
For example, if the ADV7188 loses lock, an interrupt is generated
and the
INTRQ
pin goes low. If the ADV7188 returns to the
locked state,
INTRQ
continues to be driven low until the
SD_LOCK bit is either masked or cleared.
Interrupt Drive Level
The ADV7188 resets with open drain enabled and interrupt
masking disabled. Therefore,
INTRQ
is in a high imped-
ance state after a reset. Either 01 or 10 must be written to
INTRQ_OP_SEL [1:0] for a logic level to be driven out from
the
INTRQ
pin.
It is also possible to write to a bit in the ADV7188 that manually
asserts the
INTRQ
pin. This bit is MPU_STIM_INTRQ.
INTRQ_OP_SEL [1:0], Interrupt Duration Select,
Address 0x40 [1:0], User Sub Map
Table 99. INTRQ_OP_SEL [1:0] Function
INTRQ_OP_SEL [1:0] Description
00 (default) Open drain
01 Driven low when active
10 Driven high when active
11 Reserved
Multiple Interrupt Events
If an interrupt event occurs and then another interrupt event
occurs before the system controller has cleared or masked the
first interrupt event, the ADV7188 does not generate a second
interrupt signal. Therefore, the system controller should check
all unmasked interrupt status bits because more than one may
be active.
Macrovision Interrupt Selection Bits
The user can select between pseudosync pulse and color stripe
detection as outlined in
Table 1 00 .
MV_INTRQ_SEL [1:0], Macrovision Interrupt Selection
Bits, Address 0x40 [5:4], User Sub Map
Table 100. MV_INTRQ_SEL [1:0] Function
MV_INTRQ_SEL [1:0] Description
00 Reserved
01 (default) Pseudosync only
10 Color stripe only
11 Either pseudosync or color stripe
Additional information about the interrupt system is detailed in
Table 107.