Multiple Interrupt Events; Rx Section - Analog Devices ADV7850 Hardware Manual

Function
mpu_stim_intrq_mb2
0 
1

Multiple Interrupt Events

15.2.4
If an interrupt event occurs, and then a second interrupt event occurs before the system controller has cleared or masked the first
interrupt event, the ADV7850 does not generate a second interrupt signal. The system controller should check all unmasked interrupt
status bits as more than one may be active.
15.3

RX SECTION

This section describes the interrupt support provided for the HDMI Rx inputs for the ADV8750. The HDMI Rx interrupts are or' e d
together and can be connected to either the INT1 or the INT2 pin.
The ADV7850 Rx interrupt architecture provides the following types of bits:
•
Raw bits
• Status bits
•
Interrupt mask bits
• Clear bits
Raw bits are defined as being either edge-sensitive or level-sensitive. The following compares avi_info_raw and new_avi_info_raw to
demonstrate the difference.
avi_info_raw, IO, Address 0x60[0] (Read Only)
This readback indicates the raw status of the AVI InfoFrame detected signal. This bit is set to one when an AVI InfoFrame is received
and is reset to 0 if no AVI InfoFrame is received for more than seven VSyncs(on the eighth VSync leading edge following the last
received AVI InfoFrame), after an HDMI packet detection reset or upon writing to AVI_PACKET_ID.
Function
avi_info_raw
0 
1
new_avi_info_raw, IO, Address 0x79[0] (Read Only)
This readback indicates the status of the new AVI InfoFrame interrupt signal. When set to 1, it indicates that an AVI InfoFrame was
received with new contents. Once set, this bit remains high until the interrupt is cleared via new_avi_info_clr.
Function
new_avi_info_raw
0 
1
In the case of avi_info_raw, this bit always represents the current status of whether or not the part is receiving AVI InfoFrames. It is not a
latched bit and never requires to be cleared. This is the definition of a level-sensitive raw bit.
This strategy would not work in the case of new_avi_info_raw. If the new_avi_info_raw bit were to behave in the same way as
avi_info_raw it would go high at the instant the new InfoFrame was received, and would go low again some clock cycles afterwards. This
is because a new InfoFrame is new only for the instant it is received and, once received, it is no longer new so the event to set this bit only
lasts for an instant and is then gone.
Having a raw bit that is only held high for an instant is not useful. Therefore, for these types of events, the raw bit is latched, and must be
cleared by the corresponding clear bit. Accordingly, the raw bit does not truly represent the current status; instead it represents the status
Rev. A May 2012
Description
Disable manual forced interrupt for INT2
Enable manual forced interrupt for INT2
Description
No AVI InfoFrame received within last seven VSyncs or since last HDMI packet detection reset
AVI InfoFrame received within last seven VSyncs
Description
No new AVI InfoFrame received
AVI InfoFrame with new content received
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ADV7850