Announcements
IMPORTANT: Cypress Developer Community is transitioning on October 20th. To learn more and be prepared for this change, check out our latest announcement.
cancel
Showing results for 
Search instead for 
Did you mean: 

Knowledge Base Articles

Toggling the CY7C64113's GPIO

Anonymous
Not applicable

Toggling the CY7C64113's GPIO

Question: I would like to rapidly change the CY7C64113's GPIO lines between input and output to implement a bi-directional bus. Is there any problem in switching between in and out or is there a limit to the rate this can be done?

 

Answer:

To switch between input and output, you need to change the GPIO configuration which might take about 8 instructions, each instruction typically takes 5 clock cycles (each clock cyle is 1/12MHz). Therefore, to change the GPIOs from one mode to another, the processor would need about 40 clock cycles + trise/fall (each clock cyle is 1/12MHz). Sum all these up, the total time needed is approximately 3.3us.

0 Likes
Version history
Revision #:
1 of 1
Last update:
‎Jun 22, 2011 05:31 AM
Updated by:
Anonymous
 
Contributors