Posted on May 15, 2015 at 17:26I totally agree, the problem are for sure not so perfect timings of the command (WR,CS,DC) and data line.
Maybe you already done it but you can try to rise the PLL of the SSD, right now I am using:
//SOFTWARE RESET
mySSD_Write_cmd(0x01);
delay_ms
(5);
//EXIT SLEEP
mySSD_Write_cmd(0x11);
delay_ms
(5);
//WHITE SCREEN
mySSD_Write_cmd(0x28);
delay_ms
(5);
//SET THE INTERNAL PLL NM
mySSD_Write_cmd(0xE2);
delay_ms
(5);
//As the MPU runs FMC at 84Mhz
mySSD_Write_data(47);
delay_ms
(5);
//Set Multiplier to 47
mySSD_Write_data(0);
delay_ms
(5);
//Set Divider to 1
mySSD_Write_data(0x0004);
delay_ms
(5);
//
Set 10Mhz*48/1=480Mhz PLL clock
//ENABLE PLL
mySSD_Write_cmd(0xE0);
delay_ms
(5);
mySSD_Write_data(0x0001);
delay_ms
(5);
//Reference clock , Enable PLL
mySSD_Write_cmd(0xE0);
delay_ms
(5);
mySSD_Write_data(0x0003);
delay_ms
(5);
//PLL clock , Enable PLL
//SOFTWARE RESET
mySSD_Write_cmd(0x0001);
delay_ms
(5);
//Wait a stable condition
You also have to /4 all the LCD refresh timings... but maybe I misunderstood the manual of the SSD.
With this configuration I'm able to run a frame buffer in external SDRAM ( 64Mbits of the discovery kit) with really good performance, given the fact that i run at standard 168Mhz, pll-p = 2, AHB/1, AHB1/4, AHB2/2 --> FMC Extended mode, Data-Setup-time=3 (other at zero). This gave me 34ms refresh time on 800x480 (only if i use DMA).
1HCLK should be fine, 8080 timing from p79 of ssd data-sheet show a 1ns Address-set-up at 9ns PLL clock period (111Mhz). Maybe things gets a little bit tricky with the Address-hold, data hold at the end.. unfortunately neither my future logic analyser will be able to detect such small amount of time and show me whats really happening at full speed... i'm still a student and sadly i cannot afford a real good one.
