Hi
I am now trying to get the LPDDR4 on customized board with i.mx8mq to work but face some problem.
The configuration is generated by the MX8M_LPDDR4_RPA_v29.
There's a question towards all the DFI clock related registers in the RPA, for example, the PRE_CKE_X1024 in DDRC_INIT0.
In the programming aid, the PRE_CKE_X1024 calculation formula: LPDDR4: tINIT3 of 2 ms (min)
When the controller is operating in 1:2 frequency ratio mode, program this to JEDEC spec value divided by 2, and round it up to the next integer value.
Then the PRE_CKE_X1024 should be calcluated as: 2ms/2 = 1ms (since the controller is operating in 1:2 frequency ratio mode).
If my understanding is correct, for DDR frequency 1600MHz(3200MTS), the DFI frequency should be 800MHz.
And the PRE_CKE_X1024 is in the unit of 1024 DFI clock, which is 1024/(800*10^3) ms, so 1ms should be around 781 of 1024 DFI clocks.
But in the RPA, the configuration is set to 1564.
Please help if there's any misunderstanding.
Hi Jay
for frequencies it is necessary to fill parameters as below, all other parameters
are calculated automatically
Best regards
igor
Thanks for your reply.
But my question is not answered