Voltage-Level

mtiegges9 · ‎2005-12-08

Posted on December 08, 2005 at 10:42

Voltage-Level

mtiegges9 · ‎2011-05-17

Posted on May 17, 2011 at 12:09

Hello!

in the data sheet of the ÂµPSD3354D (VDD: 5V, VCC: 3,3V) from January 2005 on the page 207 it is indicated that Port 0.1.2.3.4, XTAL1 and RESET are 5V tolerant.This contradicts the data on the page 13, it is described that only Port3 and Port4 may be operated by the MCU module with 5V.

Are Port0 and Port2 (address-DATA bus) 5V tolerant, and can they communicate with an 5V-Level external periphery???

Best regards

mt

jim239955_stm1 · ‎2011-05-17

Posted on May 17, 2011 at 12:09

Yes, you can use 5v devices on the data/add bus of the 'D' part. I have memory mapped several 5v logic devices to the bus. My understanding is that the 3.3v CPU core is 5v Tol on the data and address bus. The PSD core is not tolerant. This is why they have a D(5v) and a non-D(3.3v) version.

Note that logic high will be only 3.3 on drive for cpu core signals and 5v from the PSD ports. You must check your 5v part to make sure you will have a good margin around the switching voltage.