Key Points to Note in Programming

Zynq UltraScale+ Device Technical Reference Manual (UG1085)

Document ID
UG1085
Release Date
2022-09-15
Revision
2.3 English

1.Changing the burst length (BL) in real time is not supported. It is expected that, after a burst length is chosen it is kept unchanged. If you must change the BL, then the previous programming sequence must be followed. The same applies to changing video resolution and pixel format.

2.The suggested programming sequence (for DisplayPort and DPDMA together).

a.Program the DisplayPort source controller (see Source Controller Setup and Initialization).

b.Program the AV buffer manager.

c.Program the DPDMA.

3.Follow this sequence for disabling the DPDMA channel.

a.Disable DPDMA (Table: Disable DPDMA).

b.Disable channel and output stream in AV buffer manager.

c.Disable DisplayPort source controller.

d.This is a requirement from DPDMA. The DisplayPort controller is agnostic whether DPDMA is enabled first.

4.When blending is enabled, make sure to program the RGB_MODE bit of layer 0 and layer 1 control registers (0xA018 and 0xA01C). If the blender output is RGB data, this bit must be set to 1. For YUV, this bit should be 0. Whenever palette graphics are used, this bit must be set to 1 (even if the palette is filled with YUV).

Table 33-22:      Disable DPDMA

Task

Register

Register Field

Register Offset

Bits

Value

Pause required DPDMA channel (CHx).

DPDMA_CHx_CNTL

PAUSE

0x0218 (CH0)

1

1b'1

Wait until the DPDMA transfers over on the channel.

DPDMA_ISR

no_ostand_tran0

0x04

6

Read and write to clear

Clear DPDMA enable.

DPDMA_CHx_CNTL

EN

0x218 (CH0)

0

1b'0

Clear pause required DPDMA channel (CHx).

DPDMA_CHx_CNTL

PAUSE

0x0218 (CH0)

1

1b'0