On 04/06/2017 12:12 AM, Luke Kenneth Casson Leighton wrote:
now, i _could_ convert to eMMC but it's too much of a major redesign: it involves disrupting the RGB/TTL tracks, and may require at least two more rounds of pre-production prototyping...
... it's too much: it's too risky... and i'm getting fed up. so. what i'm going to do instead is: cut the NAND IC entirely, then wire SDC2 (which is the same pins as the NAND) to the *ON-BOARD* Micro-SD card slot, instead.
Not that I'm against dual SD slots, but from what I see, NAND and eMMC share the same pins so it should be easy enough to add the bga footprint and the required passives.
The MarsBoard A20 has pads for both NAND and eMMC in the same footprint so you can use one or the other without losing board space.
http://www.haoyuelectronics.com/service/A10-A20/Schematics/CM-A10&A20/