Timing Diagram For Last Irq - Samsung S5PC110 Manual

S5PC110_UM

2.7.6 TIMING DIAGRAM FOR LAST IRQ

The IRQ (except LastIRQ) is generated before image capture. Last IRQ specifies the end of camera signal
capture. It can be set by the timing diagram shown in
frame command. Therefore, for proper Last IRQ, you should follow the next sequence between LastIRQEn and
ImgCptEn/ ImgCptEn_Sc.
It is recommended that ImgCptEn/ ImgCptEn_SC is set at the same time and at the end of SFR setting in ISR.
FrameCnt specifies the next frame count. It is read in ISR.
As shown in 2-17, the last captured frame count is "1", that is, Frame 1 specifies the last captured frame
Figure
among frame 0~3. FrameCnt is increased by 1 at IRQ rising. The DMA input is selected by setting SFR. In this
case, IRQ is generated after Output DMA operation is completed per frame. The SFR setting (ENVID_M '0' →
'1') makes this mode aware of the starting point, and therefore, this mode does not require IRQ of starting point
and LastIRQ. FrameCnt is increased by 1 at ENVID_M (InputDMA start) low to rising ('0' → '1') and
ImgCptEn_SC '1'.
VSYNC
ImgCptEn(cmd)
LastIRQEn
IRQ
FrameCnt
VSYNC
ImgCptEn(cmd)
LastIRQEn
IRQ
FrameCnt
VSYNC
IRQ
Figure 2-17
ISR region ISR region
LastIRQEn
①
High
3 0 1
Capture O Capture O
(Frame_3) (Frame_0)
Figure 2-16 Timing Diagram for Last IRQ (LastIRQEn is Enabled)
ISR region ISR region
3 0 1
Capture O Capture O
(Frame_3) (Frame_0)
A = 9 cycle of pixel clock + 5 cycle of system clock
A
B
Diagram for Last IRQ (LastIRQEn is Disabled) and Timing Requirement
2-16. LastIRQEn specifies the ISR setting for next
Figure
ISR region ISR region
ImgCptEn
②
Low
LastIRQEn
③
Low
Last IRQ
High
2 3
Capture O Capture X
(Frame_1)
ISR region ISR region
Last IRQ
Low
2 2
Capture O Capture X
(Frame_1)
B = 1 cycle of system clock
(pulse interrupt mode)
2 1BCAMERA INTERFACE
ISR region ISR region
0 1
Capture O Capture O
(Frame_3) (Frame_0)
ISR region ISR region
3 0
Capture O Capture O
(Frame_3) (Frame_0)
ISR region
ISR region
2-18