IMX6ULL: Can not do read/write from extern RAM via EIM

[liqi_wu]

Hi, I use IMX6ULL and there is a extern RAM connect via EIM interface. I want to do read/write extern RAM, but it failed.

I captured the EIM_CS0 signal and found the signal is very strangely. 

Why the EIM_CS0 become LOW so long(more than 2us)?

and Why there is 32 noise while EIM_CS0 is LOW?

------------------------------------------------------------------my use case and configuration

//EIM clock confige 100MHZ

CLOCK_SetMux(kCLOCK_EimSlowMux, 2);
CLOCK_SetDiv(kCLOCK_EimSlowDiv, 1);

//EIM register confige, which is refer the Reference Manual

EIM->CS0GCR1 = 0x403104b1;
EIM->CS0RCR1 = 0x0b010000;
EIM->CS0RCR2 = 0x00000008;
EIM->CS0WCR1 = 0x0b040040;

//test case(read memory)

data = *((REG16 *)0x50000000);

[igorpadykov]

Hi liqi

for adjusting EIM parameters may be useful to look at app note

Interfacing Spansion® GL MirrorBit® Family to Freescale™ i.MX31 Processors

https://www.cypress.com/file/207256/download 

and sect.4.9.3 External Interface Module (EIM)

i.MX 6ULL Applications Processors for Consumer Products

Best regards
igor
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