Questions about eLCDIF register of i.MX7D

[ko-hey]

Hi all

I have several questions about eLCDIF register of i.MX7D.

Q1. Question about DATA_SELECT field of eLCDIF General Control Register in P3657.

1-1

I read section 13.2 but can't understand a difference of "Command mode" and "Data mode".
Is there any description for it ?
Could you explain the "Command mode" and "Data mode" ?

1-2

There are following description.

""Command Mode. DCn signal is Low""

However, there are no description about "DCn".
What is DCn signal ?

Q2. Question about MASTER field of eLCDIF General Control Register in P3658.

2-1

My understanding is as below. Am I correct ?

In MPU i8080 mode, user set MASTER field to "1" when Write.
In MPU i8080 mode, user set MASTER field to "0" when Read.

2-2

Does the "PIO mode" mean "program I/O mode" ?

If above understanding is uncorrect, please explain the meaning and function.

Q3. Question about OUTSTANDING_REQS field of eLCDIF General Control2 Register in P3662.

1

Let me confirm the meaning of "Number of outstanding transaction".

The meaning of "Number of outstanding transaction" is that how many untransmitted data can be held of the transmission data in Master mode (default is 2 data) ?
Is it like an internal buffer?

Ko-hey

[igorpadykov · Accepted solution]

Hi Ko-hey

Q1.  DCn signal is LCD_RS, selects between command and data mode of mpu lcd interface.
Description of "Command mode" and "Data mode" can be found in LCD datasheets.
From sect.13.2.4.6 MPU Interface  i.MX7D  RM:
"LCD_RS signal is typically used to switch between command and data modes."

>2-1

right

>2-2

right

Q3. >The meaning of "Number of outstanding transaction" is that how many untransmitted
data can be held of the transmission data in Master mode (default is 2 data) ?

this is right understanding, note "outstanding transaction" may refer not only to data but also commands.

>Is it like an internal buffer?

yes

Best regards
igor
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