2560pix = 5120 bytes
512px
2048px
Circular buffer status when stall
occurs
Circular buffer status after SBL
flush
W0
Unused space
Written before stall
Written after stall. Buffered at RESIZER output inside SBL
Written after stall. Buffered between RESIZER an PREVIEW module output inside SBL
W1
camisp-163
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Camera ISP Functional Description
Example 6-1. Camera ISP Circular Buffer Example of 4x Digital Zoom Use: (continued)
Figure 6-101. Camera ISP Circular Buffer Control Feedback Loop Example
The CODEC reads data from the circular buffer and flag windows as done. In this example, the stall
command is released when the CODEC has completed processing W0 and W1. The camera ISP resumes
writing into W3.
NOTE:
Software can control the minimum full window count to issue the stall command using the
[7:4] BCF register. Setting this value to 1 or 2 in this example may negatively
affect the performance, because only up to two or three windows can be used.
6.4.10.3.1.2 Camera ISP Circular Buffer Extended Slice Mode
In extended slice mode, both circular buffers managed by the CBUFF module are used together. One
provides address translation for the read data flow, and the other for a write data flow.
1237
SWPU177N – December 2009 – Revised November 2010
Camera Image Signal Processor
Copyright © 2009–2010, Texas Instruments Incorporated