cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC 5, 3 & 1 MCU

noha_3407421
New Contributor II

Dear Sir/Madam,

I have a question about CY8C22645.

CY8C22645 is mounted on the board.

Q.

When the CY8C22645 is not turned on, what is the state of I/O?

Is it Hi-Z?

Best Regards,

0 Likes
1 Solution
masu_1341616
New Contributor II

Hi Sampath-san,

Thank you for your reply.

I understand from the information received from you as follows.

If power is not supplied to CY8C22645, the following IO is Hi-Z.

P0[0] - P0[7]

P1[0] - P1[7]

P2[0] - P2[7]

P3[0] - P3[7]

P4[0] - P4[5]

Is my understanding correct?

Best Regards,

Harukawa

View solution in original post

0 Likes
4 Replies
SampathS_11
Moderator
Moderator

Hello Noritomo-san,

When CY8C22645 is not powered on, and some other outputs are connected to the GPIO pins, the GPIO itself will be in high impedance mode. But the ESD diodes will conduct from the GPIO to VDD and try to power CY8C22645. This may lead to the ESD diode failing, or the PSoC getting reset frequently. In such cases the addition of a series resistance will limit the current through the ESD diode. The resistance can be around a few hundred ohms.

Are you facing any issue because of which you asked this question?

Sampath Selvaraj

0 Likes
masu_1341616
New Contributor II

Hi Sampath-san,

Thank you for your reply.

I understand from the information received from you as follows.

If power is not supplied to CY8C22645, the following IO is Hi-Z.

P0[0] - P0[7]

P1[0] - P1[7]

P2[0] - P2[7]

P3[0] - P3[7]

P4[0] - P4[5]

Is my understanding correct?

Best Regards,

Harukawa

View solution in original post

0 Likes
SampathS_11
Moderator
Moderator

Hi Harukawa-san,

Your understanding is correct.

Thanks, and regards,

Sampath

0 Likes
noha_3407421
New Contributor II

Hi Sampath-san,

Thank you for your reply.

I think that the question can be closed with this answer.

Thank you for cooperation.

Best Regards,

Harukawa

0 Likes