I chose to put this question here because it is just choosing a chip. I will post in project or MCU section later should I encounter any issues.
Over the years I have developed an audio DAC technology consists an ADSP-BF706 as interpolation engine, iCE40HX8K as SDM/DEM engine and a thermostat 4-bit DAC is used for final DAC conversion.
What I want to do is to make this a portable music player, not just a sound card. I plan to use an ARM processor to run Linux, which handles GUI, USB, decoder and DSP algorithm.
The ARM directly talks to FPGA using a parallel bus, thus eliminating the need of a dedicated DSP chip.
Here is a list of what the processor needs in order to make this happen:
1. 500MHz+ with NEON, power <0.5w at half speed, power <0.8w at full speed.
2. Can be routed with 5mil/5mil traces and 10mil/18mil vias.
3. Supports DDR3L-800 x16. Supports eMMC at 40MB/s+ speed.
4. At least one USB2.0 device interface.
5. MIPI or 16-bit RGB controller, 320*480 or higher.
6. A parallel port that supports 8-bit*100MHz with frame sync, slave mode preferred.
7. Supports suspend to RAM and soft power off.
8. Runs Linux with Mono/Winforms or Mono/Gtk#.
So far I've been looking at iMX6UL/ULL and AM3352. The former doesn't have slave mode parallel interface, and the latter consumes too much power.
Do you have any good suggestions on which ARM processor to use? Or can you suggest me another that suits my needs?
Final decision:
i.MX6ULL, with 528MHz Cortex-A7 w/NEON, LCD controller and EIM external bus interface.
Already ordered the official dev kit for this chip, seems promising to me.