Who make D3x/s's sensors ?

Started Nov 23, 2009 | Discussions thread
nilux
Regular MemberPosts: 429
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Re: The plot just gets thicker: an authoritative answer
In reply to Thom Hogan, Dec 1, 2009

Thom Hogan wrote:

Brad Morris wrote:

Sorry you are wrong again. An ASIC is a specialized, application specific Central Processing Unit (CPU).

No, it is not. ASIC stands for Application-specific Integrated Circuit. An ASIC may or may not contain one or more processors in it, but it is not generally regarded as a "processor." Moreover, getting back to the original thrust of your argument--that because you saw different Copyright notices in different firmware that the firmware itself was written by different companies--an ASIC can have flash memory in it that can be rewritten, too. Thus, a firmware update could, in theory, update code in an ASIC. Given that the Nikon ASIC contains IP from companies other than Nikon (and several companies, I believe), any given firmware update could be just updating a flash section in the ASIC.

In this case, Nikon Camera ASICs are specialized image processing CPUs.

I suspect that there are several different dedicated processors within the EXPEED chip. Each of which is optimized to the task it has to perform. But your contention that they run an OS, etc., is probably wrong. It's not the way I'd design an ASIC, as it would be too inefficient to put too many layers of code on top of the processor itself. The ASIC's processors are almost certainly running low-level, dedicated code.

I used to work at a company that designed chips for point and shoot digital cameras. We supported a few different image sensors. Our chip basically handled everything else. We had a USB IO interface, IO for flash (SD and I think 2 other standards), DDR memory interface, LCD driver, more IO to talk to the sensor, and a few to read settings from the buttons and switches on the camera. The core area had 1-2 ARM CPUs, a large section of dedicated hardware for JPEG encoding, video encoding, and the other logic to support USB, memory controller, etc.

The software group used a real time OS (RTOS) that ran on the ARM that was used for the user interface. By UI I mean all the menus on the back to adjust settings etc. The ARM also ran audio encoding software for the videos. The ARM was too slow for JPEG and video encoding which is why we had all the dedicated hardware that took up half our chip.

The software that ran on the ARM was stored in firmware (a separate flash chip on the board) This was routinely updated as we fixed minor bugs, revised the UI menus, added support for Chinese language fonts etc. Since our audio was done on the CPU it also got a few upgrades. The imaging JPEG/video engine was locked in hardware. The only real variables were the input resolution data, white balance, and maybe one or two other settings.

This was a few years ago but I doubt things have changed a huge amount.

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