Key difference between AM335x and AM37x

You can go to http://www.ti.com/lsds/ti/arm/sitara_arm_cortex_a_processor/products.page and once you check AM335x parts and AM37xx parts, the table will show you the main differences in terms of peripherals

Additional resources if you were looking for AM335x vs AM37x

http://processors.wiki.ti.com/index.php/AM37x_To_AM335x_Hardware_Migration_Guide

If you were looking for AM335x vs AM437x

http://processors.wiki.ti.com/index.php/AM335x_to_AM437x_Hardware_Migration_Guide

Regards

Mukul 

Although partcodes may be similar, there are several different series of processors branded "Sitara".

In roughly chronological order, to the best of my knowledge:

• AM1xxx, these are OMAP-L1xx ARM9+DSP series but without DSP functionality (the same chips whose ARM core is disabled are known as the C674x DSPs).  They remain very much DSP-like architecturally, with CBA-based interconnect.  Includes PRUSSv1.
• OMAP3-family, with Cortex-A8 processor and Sonics-MX interconnect:
  • AM35xx, this is an OMAP34xx/35xx-derivative but genuinely a different die: architectually still OMAP3, but simplified power management and various peripherals substituted and added to make it more well-suited for broadmarket applications (as opposed to smartphones).
  • AM37xx, this is an OMAP36xx/DM37xx but with the IVA/DSP subsystem disabled.  The fact that it's really still an OMAP shows for example in that it uses mDDR memory, has a camera interface, yet no Ethernet.
• OMAP4-generation (but quite different nonetheless), with Cortex-A8 or -A9 processor and FlexNOC interconnect:
  • AM389x, this is the DM816x "Netra" but without DSP / video accelerators
  • AM387x, this is the DM814x "Centaurus" but without DSP / video accelerators
  • AM335x "Subarctic", targeted for industrial applications.  It is quite similar to the previous two chips architectually, but with a significantly different set of peripherals.  First chip since the AM1xxx to include PRUSS again (upgraded version thereof).
  • AM437x "Aegis", the latest of the bunch: the first to have a cortex-A9 instead of -A8.

All of them have substantial differences in the peripherals available, so you should check carefully which peripherals are important to you.