Hi,
I am using my own design with IMXRT1062. I have connected S70KS1281 hyperram chip to FLEXSPI2 interface. All initialization of hyperram is based on AN12239SW example project.
Hyperram is working, I am able to do read/write test on address range 0x70000000 - 0x71000000 without any errors. But I have problem with LCD frame buffer located in hyperram address range. If I am displaying static picture on the display, it is working well. But if I draw some points and lines to frame area, Image on the display is shifted to the side. I tried to change frame buffer location from hyperram to OC ram, and inside OC ram, the same source code is working well.
I think this is somehow related to switching between read and write operations on flexspi. I am doing a write operations inside main loop. And LCD driver is doing DMA read operations on backgroud.
My function for drawing pixels in main loop is looking like this:
#define LCD_FRAME 0x70800000
void Point(uint16_t color, uint16_t x, uint16_t y)
{
uint32_t addr = LCD_FRAME + (2 * x) + (y * 800 * 2);
*(uint16_t*)addr = color;
}And I have this result on display:
Then I modified draw function like this:
#define LCD_FRAME 0x70800000
void Point(uint16_t color, uint16_t x, uint16_t y)
{
while (!FLEXSPI_GetBusIdleStatus(FLEXSPI2))
{
}
uint32_t addr = LCD_FRAME + (2 * x) + (y * 800 * 2);
*(uint16_t*)addr = color;
}And it solved the problem:
But I think this is not good solution. I think DMA controller should take care about this conflicts automatically...
This is my MPU configuration, maybe there is a problem, I donk know. I tried all permutations of MPU settings without luck. Region 8 is hyperram nocache area used for frame buffer:
/* MPU configuration. */
void BOARD_ConfigMPU(void)
{
/* Disable I cache and D cache */
if (SCB_CCR_IC_Msk == (SCB_CCR_IC_Msk & SCB->CCR))
{
SCB_DisableICache();
}
if (SCB_CCR_DC_Msk == (SCB_CCR_DC_Msk & SCB->CCR))
{
SCB_DisableDCache();
}
/* Disable MPU */
ARM_MPU_Disable();
/* MPU configure:
* Use ARM_MPU_RASR(DisableExec, AccessPermission, TypeExtField, IsShareable, IsCacheable, IsBufferable,
* SubRegionDisable, Size)
* API in core_cm7.h.
* param DisableExec Instruction access (XN) disable bit,0=instruction fetches enabled, 1=instruction fetches
* disabled.
* param AccessPermission Data access permissions, allows you to configure read/write access for User and
* Privileged mode.
* Use MACROS defined in core_cm7.h:
* ARM_MPU_AP_NONE/ARM_MPU_AP_PRIV/ARM_MPU_AP_URO/ARM_MPU_AP_FULL/ARM_MPU_AP_PRO/ARM_MPU_AP_RO
* Combine TypeExtField/IsShareable/IsCacheable/IsBufferable to configure MPU memory access attributes.
* TypeExtField IsShareable IsCacheable IsBufferable Memory Attribtue Shareability Cache
* 0 x 0 0 Strongly Ordered shareable
* 0 x 0 1 Device shareable
* 0 0 1 0 Normal not shareable Outer and inner write
* through no write allocate
* 0 0 1 1 Normal not shareable Outer and inner write
* back no write allocate
* 0 1 1 0 Normal shareable Outer and inner write
* through no write allocate
* 0 1 1 1 Normal shareable Outer and inner write
* back no write allocate
* 1 0 0 0 Normal not shareable outer and inner
* noncache
* 1 1 0 0 Normal shareable outer and inner
* noncache
* 1 0 1 1 Normal not shareable outer and inner write
* back write/read acllocate
* 1 1 1 1 Normal shareable outer and inner write
* back write/read acllocate
* 2 x 0 0 Device not shareable
* Above are normal use settings, if your want to see more details or want to config different inner/outter cache
* policy.
* please refer to Table 4-55 /4-56 in arm cortex-M7 generic user guide <dui0646b_cortex_m7_dgug.pdf>
* param SubRegionDisable Sub-region disable field. 0=sub-region is enabled, 1=sub-region is disabled.
* param Size Region size of the region to be configured. use ARM_MPU_REGION_SIZE_xxx MACRO in
* core_cm7.h.
*/
/* Region 0 setting: Memory with Device type, not shareable, non-cacheable. */
MPU->RBAR = ARM_MPU_RBAR(0, 0xC0000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 2, 0, 0, 0, 0, ARM_MPU_REGION_SIZE_512MB);
/* Region 1 setting: Memory with Normal type, not shareable, non-cacheable. */
MPU->RBAR = ARM_MPU_RBAR(1, 0x70000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_1GB);
/* Region 2 setting */
#if defined(XIP_EXTERNAL_FLASH) && (XIP_EXTERNAL_FLASH == 1)
/* Setting Memory with Normal type, not shareable, outer/inner write back. */
MPU->RBAR = ARM_MPU_RBAR(2, 0x60000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_RO, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_8MB);
#else
/* Setting Memory with Device type, not shareable, non-cacheable. */
MPU->RBAR = ARM_MPU_RBAR(2, 0x60000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_RO, 2, 0, 0, 0, 0, ARM_MPU_REGION_SIZE_8MB);
#endif
/* Region 3 setting: Memory with Device type, not shareable, non-cacheable. */
MPU->RBAR = ARM_MPU_RBAR(3, 0x00000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 2, 0, 0, 0, 0, ARM_MPU_REGION_SIZE_1GB);
/* Region 4 setting: Memory with Normal type, not shareable, outer/inner write back */
MPU->RBAR = ARM_MPU_RBAR(4, 0x00000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_128KB);
/* Region 5 setting: Memory with Normal type, not shareable, outer/inner write back */
MPU->RBAR = ARM_MPU_RBAR(5, 0x20000000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_128KB);
/* Region 6 setting: Memory with Normal type, not shareable, outer/inner write back */
MPU->RBAR = ARM_MPU_RBAR(6, 0x20200000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_512KB);
/* Region 7 setting: Memory with Normal type, not shareable, outer/inner write back */
MPU->RBAR = ARM_MPU_RBAR(7, 0x20280000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 0, 0, 1, 1, 0, ARM_MPU_REGION_SIZE_256KB);
/* Region 8 setting: Memory with Normal type, noncache, */
MPU->RBAR = ARM_MPU_RBAR(8, 0x70800000U);
MPU->RASR = ARM_MPU_RASR(0, ARM_MPU_AP_FULL, 1, 0, 0, 0, 0, ARM_MPU_REGION_SIZE_8MB);
/* Enable MPU */
ARM_MPU_Enable(MPU_CTRL_PRIVDEFENA_Msk);
/* Enable I cache and D cache */
SCB_EnableDCache();
SCB_EnableICache();
}Does anyone understand this problem? It is possible to use hyperram for LCD frame buffer?
Hi Peter,
From our internal test result, the HyperRAM performance versus SDRAM, which SDRAM read throughput rate (ARM core read) is slower than HyperRAM:
HyperRAM MPU config:
non-shareable
Cacheable
Write back
Enable Dcache
best regards,
Mike
Hi Peter,
First of all, sorry for the later reply.
From your provide "flexspi_ahbcmderror.logicdata", the HyperRAM stop working during the third memcpy.
I am checking with i.MXRT product team about this issue.
Thanks for the patience.
best regards,
Mike
