camisp-085
relocatable
External VS
CCDC_VD0_IRQ,
CCDC_VD1_IRQ
camisp-086
relocatable
External VS
CCDC_VD0_IRQ,
CCDC_VD1_IRQ
camisp-087
External VS
WEN
CCDC_
2_IRQ
VD
Public Version
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Camera ISP Basic Programming Model
If
[2] VDPOL is 0, the CCDC_VD0_IRQ and CCDC_VD1_IRQ HS counters begin
counting HS pulses from the rising edge of the external VS, as shown in
Figure 6-112. Camera ISP CCDC CCDC_VD0_IRQ/CCDC_VD1_IRQ Interrupt Behavior When VDPOL = 0
If
[2] VDPOL is 1, the CCDC_VD0_IRQ and CCDC_VD1_IRQ HS counters begin
counting HS pulses from the falling edge of the external VS.
Figure 6-113. Camera ISP CCDC CCDC_VD0_IRQ/CCDC_VD1_IRQ Interrupt Behavior When VDPOL = 1
6.5.6.3.3 Camera ISP CCDC CCDC_VD2_IRQ Interrupt
In addition to the CCDC_VD0_IRQ and CCDC_VD1_IRQ interrupts, the CCDC has an interrupt called
CCDC_VD2_IRQ. This interrupt always occurs at the falling edge of the WEN signal (through external
pin). There are no registers in the CCDC module to configure this interrupt (see
).
Figure 6-114. Camera ISP CCDC CCDC_VD2_IRQ Interrupt Behavior
6.5.6.3.4 Camera ISP CCDC Status Checking
The
1] BUSY status bit is set when the start of frame occurs (if the
[0] ENABLE
bit is 1 at that time). It is automatically reset to 0 at the end of a frame. The
[1] BUSY status
bit may be polled to determine end-of-frame status.
The
[16] FPERR status bit is set when faulty-pixel data fetched from memory arrives late. This
bit can be reset by writing a 1 to the bit.
6.5.6.4
Camera ISP CCDC Register Accessibility During Frame Processing
There are three types of register access in the CCDC:
•
Shadowed registers: In the CCDC, two register fields are shadowed in different ways. Shadowed
registers can be read and written at any time, but the written values take effect (are latched) only at
certain times, based on some event. Reads return the most recent write, even though the settings are
not used until the specific event occurs. The shadowed registers are:
–
[0] ENABLE
•
Written values take effect only at the start of a frame event (rising edge of VD if
[2] VDPOL is positive, or falling edge of VD if
[2]
VDPOL is negative).
–
•
When
[15] VDLC is set to 0, written values take effect only at the start of a frame
1269
SWPU177N – December 2009 – Revised November 2010
Camera Image Signal Processor
Copyright © 2009–2010, Texas Instruments Incorporated