Unable to write Port 1 in PCAL6416A

[DheerajH]

Here we have configured all pins of port 0 as input mode & its working fine but facing issue in output mode of port1.

Configured Pin2, Pin3, Pin4, Pin5 & Pin6 of Port1 as output, but unable to set the Pin4 & Pin5 of Port1.

The voltage at respective pins are shown in the below table.

Port	Voltage observed when pin is set to HIGH(V)	Voltage observed when pin is set to LOW(V)
Port1	Pin2 - 3.3 Pin3 - 3.3 Pin4 - 1.0 (Expected 3.3V) Pin5 - 1.0 (Expected 3.3V) Pin6 -  3.3	Pin2 - 0 Pin3 - 0 Pin4 - 1.0 (Expected 0 V) Pin5 - 1.0 (Expected 0 V) Pin6 - 0

 attached the Gerber and snap of the schematic in the below link.

https://drive.google.com/drive/u/0/folders/1vk8i7lA49RTkKtkloo1InNvCfmCuyQJ1

[DheerajH]

Any updates on this issue?

We have tried with QFN24 Base IC & TSSOP package IC but facing same issue in output mode.

Thank you
Dheeraj

[TomasVaverka · Accepted solution]

Hello Dheeraj,

I see you entered a case #00323999 on this topic three weeks ago. I would recommend you to re-open it so that my colleague Jozef can follow up on this along with our experts from the product group.

Best regards,

Tomas 

[DheerajH]

 We resolved the issue, there was an issue with I2C protocol

[DheerajH]

Hi Tomas, Thanks for the response...still the same problem exists.

Here we have configured all pins of port 0 as input mode & its working fine but facing issue in output mode of port1.

Configured Pin2, Pin3, Pin4, Pin5 & Pin6 of Port1 as output, but unable to set the Pin4 & Pin5 of Port1.

The voltage at respective pins are shown in the below table.

Port	Voltage observed when pin is set to HIGH(V)	Voltage observed when pin is set to LOW(V)
Port1	Pin2 - 3.3 Pin3 - 3.3 Pin4 - 1.0 (Expected 3.3V) Pin5 - 1.0 (Expected 3.3V) Pin6 -  3.3	Pin2 - 0 Pin3 - 0 Pin4 - 1.0 (Expected 0 V) Pin5 - 1.0 (Expected 0 V) Pin6 - 0

I have attached the Gerber and snap of the schematic in the below link. Please verify once

https://drive.google.com/drive/u/0/folders/1vk8i7lA49RTkKtkloo1InNvCfmCuyQJ1

[TomasVaverka]

Hello Dheeraj,

In order to configure Port x for output mode, the following registers should be initialized:

So for Port 1, you should configure registers 0x4F, 0x47, 0x49, 0x07 and 0x03. 

I hope it helps. If not, please let me know how you set the registers 0x4F, 0x47, 0x49, 0x07 and 0x03 to achieve your required configuration .

Best regards,

Tomas

[DheerajH]

Thank you Tomas for your response!!

Can you share the values to be configured to make port 1 as output mode with respect to the registers that you have mentioned above.

Below is the configuration that we have done

Register	Value	Mode
Configuration Register (06h)	0xFF	Input Mode
Pullup Enable Register (46h)	0xFF
Pullup Enable Register (47h)	0xFF
Configuration Register (07h)	0x00	Output Mode
Pullup Selection Register (48h)	0xFF
Pullup Selection Register (49h)	0xFF
Output Port Configuration Register (4fh)	0x02

Let me know any changes needs to be done in Configuration

Regards,

Dheeraj

[TomasVaverka]

Hello Dheeraj,

Looking at your configuration, you set all P1 I/Os as open-drain outputs with 100k pull-up resistors. Is this what you want to achieve? 

As I highlighted before, it is recommended to program the register 0x4F before settings the P1 I/Os as outputs. 

Are you now able to set/reset P1 outputs using the the register 0x03? If not, please let me know which outputs do not work and what is connected to them.

Best regards,

Tomas