Samsung S5PC100, User Manual, Page: 1130 / 1863

S5PC100 USER’S MANUAL (REV1.0) CAMERA INTERFACE
9.3
-15
7.6 TIMING DIAGRAM FOR LAST IRQ
IRQ except LastIRQ is generated before image capturing. Last IRQ which means camera signal capture-end can
be set by following timing diagram. LastIRQEn is ISR setting for next frame command. Therefore, for adequate
last IRQ, you should follow next sequence between LastIRQEn and ImgCptEn/ImgCptEn_Sc. It is recommended
that ImgCptEn/ImgCptEn_SC is set at same time and at last of SFR setting in ISR. FrameCnt which is read in ISR
means next frame count. On following diagram, last captured frame count is “1.” That is, Frame 1 is the last-
captured frame among frame 0~3. FrameCnt is increased by 1 at IRQ rising. DMA input can be selected by SFR
setting. In this case, IRQ is generated after Output DMA operation done per frame. This mode is aware of starting
point by user’s SFR setting (ENVID_M ‘0’
→
‘1’). Therefore, this mode does not need 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’
ISR region ISR region ISR region
VSYNC
ISR region
ImgCptEn(cmd)
LastIRQEn
Capture O Capture O Capture O Capture X
IRQ
Last IRQ
High
ISR region ISR region ISR region
FrameCnt
0 1 2 3 3 0 1
Capture O Capture O
(Frame_3) (Frame_0) (Frame_1) (Frame_3) (Frame_0)
①
②
③
LastIRQEn
High
ImgCptEn
Low
LastIRQEn
Low
Figure 9.3-13 Timing Diagram for Last IRQ (LastIRQEn is Enabled)
VSYNC
IRQ
A
B
A = 9 cycle of pixel clock + 5 cycle of system clock
B = 1 cycle of system clock
(pulse interrupt mode)
ISR region ISR region ISR region
VSYNC
ISR region
ImgCptEn(cmd)
LastIRQEn
Capture O Capture O Capture O Capture X
IRQ
Last IRQ
Low
ISR region ISR region ISR region
FrameCnt
0 1 2 2 3 3 0
Capture O Capture O
(Frame_3) (Frame_0) (Frame_1) (Frame_3) (Frame_0)
Figure 9.3-14 Diagram for Last IRQ (LastIRQEn is Disabled) and Timing Requirement