Virtual
space
Physical space
(SDRAM)
The camera
ISP writes a full
frame to the
virtual space
The circular buffer
maps virtual
addresses to
physical addresses
in SDRAM. Data is
stored in SDRAM
An other module uses
data stored in SDRAM. It
informs the CBUFF
module when it is done
with a physical buffer
Camera ISP
JPEG
CODEC
camisp-164
Read
Pointer (managed
by ARM /DSP/
sDMA)
Current
Window
Next
Window
START
W
in
d
o
w
s
iz
e
Physical space
Circular buffer
Window 0
Window 1
CPU
window
Mapped to W 0
Mapped to W 1
Mapped to W 2
Mapped to W 3
Mapped to W 0
Virtual space
END
Mapped to W 1
Mapped to W 2
Mapped to W 3
camisp-165
Public Version
www.ti.com
Camera ISP Functional Description
Figure 6-99. Camera ISP Circular Buffer Single Slice Buffer (Write Mode)
Physically, this circular buffer is typically in the SDRAM. The virtual space is defined by a start and an end
address. The physical buffer is defined by a start address, a window size, and a window count. It is
contiguous in memory.
shows the buffer organization for a 4-window buffer.
Figure 6-100. Camera ISP Circular Buffer Single Slice Buffer Example (Write Mode)
1235
SWPU177N – December 2009 – Revised November 2010
Camera Image Signal Processor
Copyright © 2009–2010, Texas Instruments Incorporated
