MPC5777M EBI for exteranl flash and SRAM

[bwp530]

We use a external flash and a external SRAM on our own board.

We use the 16-bit bus mode and DATA[16:31] signals.

CS0: 0x20000000  --- 0x20FFFFFF

CS1: 0x21000000 ---- 0x203FFFFF

I make test code as the attachment file,  it can't write data to external SRAM and the CS1 have no action.

I don't know if the configuration is right.

[davidtosenovjan]

Hi, I count point out following example code where you can see how to configure external SRAM. Unfortunatelly it is written for different device, so you will have to port it to MPC5777M. As MPC5777MEVB does not have external SRAM installed on the board, I don't see a need of such example. I believe MPC5777C example could be useful as EBI module is almost the same.

https://community.nxp.com/docs/DOC-335543 

[bwp530]

thank you, I just transplant the mpc5777C examlpe to my attachment, It can't work. So I ask this question. Could you help check my configuration? And I found some code in MPC5777C example:

static asm void External_SRAM_MMU_init(void)
{
//nofralloc

e_lis r3, 0x1002 /* Select TLB entry #, define R/W replacment control */
mtMAS0 r3 /* Load MAS0 with 0x1002 0000 for TLB entry #2 */

tlbre /* Get TLB entry # information */

mfspr r3, MAS3
//oris r3, r3, 0x2000 /* EBI Physical Base Addr changed to 0x2000_0000 */
//ori r3, r3, 0x0000
se_bseti r3,2
e_ori r3,r3,0x0000

mtMAS3 r3

msync /* make sure we finished all memory accesses */

tlbwe /* Write entry defined in MAS0 (entry 1 here) to MMU TLB */

se_isync /* Wait for tlbwe to complete, then flush instruction buffer */
//blr

}

For MPC5777M, how to configure MMU?

[davidtosenovjan]

There is MMU on the MPC5777M. This does not need to be done.