Samsung S3C2451X User Manual page 604

CAMERA INTERFACE
Timing diagram for Last IRQ (Camera capture mode)
IRQ except LastIRQ is generated before image capturing. Last IRQ which means capture-end can be set by
following timing diagram. LastIRQEn is auto-cleared and ,as mentioned, SFR setting in ISR is for next frame
command. So, for adequate last IRQ, you should follow next sequence between LastIRQEn and
ImgCptEn/ImgCptEn_CoSc/ImgCptEnPrSC. It is recommended that ImgCptEn/ImgCptEn_CoSc/ImgCptEnPrSC
are 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.
- Camera input capture path (applied both Preview & Codec path)
VSYNC
ImgCptEn(cmd)
LastIRQEn
IRQ
FrameCnt
VSYNC
ImgCptEn(cmd)
LastIRQEn
IRQ
FrameCnt 3
Timing diagram for IRQ (Memory data processing mode)
- MSDMA(Memory data input path) input is applied only preview path !!! when SFR SEL_DMA_CAM = '1' ).
Codec path doesn't care. codec path is applied a only camera capturing case. IRQ is generated after Preview
DMA operation done per frame. This mode is aware of starting point by user's SFR setting (ENVID_MS '0'
so, this mode doesn't need IRQ of starting point and LastIRQ. FrameCnt is increased by 1 at ENVID_MS low to
rising ('0' '1') and ImgCptEn_PrSC '1'
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
23-12
Specifications and information herein are subject to change without notice.
ISR ISR
region region
Auto cleared
3 0
Capture O Capture O
(Frame_3) (Frame_0)
ISR ISR
region region
0 1
Capture O Capture O
(Frame_3) (Frame_0)
VSYNC
IRQ
ISR ISR
region region
1 2
Capture O
(Frame_1)
ISR ISR
region region
2
Capture O Capture X
(Frame_1)
A = 8 cycle of pixel clock + 3 cycle of system clock
A
B = 1 cycle of system clock
B
S3C2451X RISC MICROPROCESSOR
ISR
region
Last
IRQ
3 0
Capture X Capture O
(Frame_3)
ISR
region
Last IRQ
Low
2 3
Capture O
(Frame_2)
ISR ISR
region region
1
Capture O
(Frame_0)
ISR ISR
region region
0
Capture O
(Frame_3)
'1').