IMX1052's PXP

[zhouxia]

When I read the pxp register manual of 1052, I found that the fifth bit of the [PXP_PS_CTRLn] register is WB_SWAP, which is used to exchange two bytes per 16 bits. After I used this function in the demo, the screen showed a black screen.

[gusarambula]

Hello Zhouxia,

Would you please provide more details on which demo you are running and what would you like to achieve by enabling this swap? Are you running this demo on an i.MXRT EVK?

Regards,
Gustavo

[zhouxia]

Hello Gustavo,

Thank you for your reply。

I run the "PXP_blend" demo. The input and output pixel formats of the AS plane and PS plane of the image blending routine are rgb565. This image mixing routine can run normally. I only modify swap_byte to true. I want to know what happens when this bit is true. Is it the exchanged 16-bit rgb565 input pixel value or exchanged other.

Regards,
Zhouxia

[gusarambula]

Hello zhouxia,

The WB_SWAP function swaps bytes within the 16-bit words if the PS buffer. I would recommend using this option only if your current pixel format requires it. It would affect how the pixels are managed while going in the PS buffer before the PXP processes like rotation or color conversion.

Regards,
Gustavo

[takayuki_ishii]

Hello @gusarambula 

Is WB_SWAP bit on PXP_PS_CTRL register work?

I just connect UVC camera to IMXRT1050EVK and output capture data to LCD.

Image format of capture data are Y0U0Y1V0.

So run PXP for YUV->RGB color space conversion.

CRC of PXP support only U0Y0V0Y1 byte data, but UVC camera output Y0U0Y1V0 format.

1) I think, that it is just assumed function of WB_SWAP bit. Is it correct?

2) I try to set/clear WB_SWAP bit and run CRC by PXP. but output data are same both WB_SWAP=0 and WB_SWAP=1. Is it have some limitation like FORMAT bits of PXP_PS_CTRL or PXP_OUT_CTRL?

Now I use input and output format are following.

  PXP_PS_CTRL[4:0] = 0x12 : UYVY1P422 — 16-bit pixels (1-plane U0,Y0,V0,Y1 interleaved bytes)

  PXP_OUT_CTRL[4:0] = 0x05 : RGB888P — 24-bit pixels (packed 24-bit format)

If swap capture data by CPU and run CRC by PXP, It can preview capture result by LCD.

Project base example is evkbimxrt1050_elcdif_rgb.

If you have some information, please let me know.

Best regards,

Ishii.