[AM572x] Recommend the NOR Flash for AM572x

Hi,

All NOR chips, that meet the requirements stated in device TRM ( Section 15.4.4 GPMC Functional Description,  Section 1.3.15 External Memory Interfaces) can be used with AM572x devices, that is:  

  - Asynchronous and synchronous NOR flash memories

  The GPMC can communicate with a wide range of external devices:

  -  External asynchronous or synchronous 8-bit wide memory or device (non burst device)

  -  External asynchronous or synchronous 16-bit wide memory or device

  -  External 16-bit non-multiplexed NOR flash device

  -  External 16-bit address and data multiplexed NOR Flash device

  -  External 8-bit and 16-bit NAND flash device  

  -  External 16-bit pseudo-SRAM (pSRAM) device

If you want your board to boot from NOR, you should consider the recommendations in Section 33.3.7.3 XIP Memory in AM572x TRM:    

• The GPMC is the communication interface.

• Memories up to 1Gibit (128MiB) can be connected.

• 8-bit or 16-bit data bus width, configured through sysboot[13] (=1 for 16-bit)

• Non-muxed or address/data multiplexed mode, configured through sysboot[12:11] (=0x1 for A/D mux)

• The GPMC clock is 133 MHz.

As for your second question: 

Kaka said:

According to the Figure15-77 on TRM, there is the short pulse on nCS and nOE line when A0 transits A1. Does it always happen?

There shouldn't be such pulse in the CS & OE lines. I've tested the interface of the older Sitara devices (GPMC IP is the same), and haven't seen such pulse on CS & OE. I will confirm this with the TRM authors, but IMO this is an error, when drawing the diagram. 

Best Regards, 
Yordan