i need help to sovle the imx233 circuit problem

[stevenshan]

@Artur

I make a Printed Circuit Board ,and now the result is not good,which i had tested in below,i wish you can help me.

5V in PIN102 ---VDD5V ,VDDIO --3.126V ,VDD ---1.228 ,VDDA--1.788V ,PIN119 PWS  is 2.22V, VDDM is cycle by 0.26V-0.399V,DC-DC 4P2 1.19V.

boot0--boot4 is all 0V , crystal oscillator is 24V tested by oscilloscope .

I think there are some problems with my circuit,can you help me?

[art]

Is the schematic you've provided complete? For example, I don't see any connection for the DCDC_LP and DCDC_LN pins (DCDC converter's inductor), BATT and DCDC_BATT pins (connections for an external battery), VDD4P2 (linear regulator for battery charge and DCDC converter input), PSWITCH (power switch button). Do you ever use a battery or the whole system is always powered from the VDD5V source? Do you ever use the DCDC converter, or the internal linear regulators are the only power supply for the system? Please specify.

Artur

[stevenshan]

Hi Artur

Thank you  for your reply,it is useful to me.

The schematic is provided complete with make a print circuit board,it is true that there are some problem.

Now i correct them with wire connection:

1. i  connect DCDC_LP and DCDC_LN pins with inductor 10UH with 2A.

2. VDD4P2 is DC-DC converter input? i connect nothing with it . I think DCDC converter can be power input by 5V,how can i know DCDC is convert right?

3 .i  connect PSWITCH to WDDIO by resistor 22K, so it is 2.22V.

4.The system is always powered from VDD5V no battery,i want to use DCDC converter .

5. why  VDDM oupout is cycle by 0.26V-0.399V?  it is power by VDDIO,I think it will be output right when VDDIO ouput is right .

I need your help.

best wish.

steven.

[art]

Actually, your system behaviour is as expected. When the system starts on 5V only power, the system by default is powered by internal linear regulators VDDD, VDDA and VDDIO, VDDM linear regulator is off, the DCDC converter is off, and the VDD4P2 linear regulator, that regulates the input VDD5V voltage down to 4.2V for DCDC converter input, is also off by default in that case.

In current configuration, the system always starts in the USB bootloader mode since PSWITCH is pulled up to VDDIO through a resistor. Do you plan to ever use the PSWITCH signal to generate power on/off events? If not and if the power configuration is always 5V only, it's better to pull PSWITCH down to GND.

To use the LCD_D[03:00] signals for boot configuration, you have to pull the LCD_RS pin up to VDDIO through a 10kOhm - 47kOhm resistor to enable the LCD_D[03:00] signals as boot configuration ones. Also, you have to pull the LCD_D05 pin down to GND through a 10kOhm - 47kOhm resistor to disable the ARM ETM debug feature at boot.

After that, you have to load some code, executable by i.MX233, to NAND Flash and then change the LCD_D[03:00] signals to 0b0100 to enable the NAND Flash boot. For more information, refer to the Chapter 35  "Boot Modes" of the i.MX233 Reference Manual Rev.1 document, available on the processor's Documentation web page:

http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/i.mx-applications-process...

Have a great day,
Artur

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[stevenshan]

Hello Artur

The circiut now is bootloader by usb ,so i want to download u-boot by MfgTool,but MfgTool show that can not find the USB PORT.i need  external power?

[stevenshan]

Hi Artur

Are you mean VDDM is off in my system,how can it on? if it off ,i think the external SDRAM can not be power,the uboot and linux can not work,so VDDM need to be on i think.

[art]

Yes, VDDM is off by default immediately after power-up. Software should enable it at early boot stage. For more information, refer to the Chapter 32 "Power Supply", especially, to the Section 32.11.8 "VDDMEM Supply Targets Control Register Description" of the i.MX233 Reference Manual document I mentioned earlier.

Artur

[stevenshan]

It is regret that there is no 'attach' whe i  reply.

[art]

I'm in progress of reviewing the issue, will contact you back soon.

Best Regards,

Artur