eblc1388
Active Member
Hi guys, any comments?
The following is a quote from the book, referring to PIC16C73:
Designing Embedded Hardware
By John Catsoulis
Publisher: O'Reilly
Pub Date: May 2005
ISBN: 0-596-00755-8
The following is a quote from the book, referring to PIC16C73:
Designing Embedded Hardware
By John Catsoulis
Publisher: O'Reilly
Pub Date: May 2005
ISBN: 0-596-00755-8
The reset input, /MCLR, is tied directly to the power supply, such that it is permanently inactive. In this case, we are relying on the processor's internal power-on reset circuitry and don't need to provide an external reset. It is common practice to use a pull-up resistor to tie an unused input, such as MCLR, inactive. However, in this case I have found that a pull-up resistor can affect the activation of the internal power-on reset to the point where it fails to kick in. (The internal capacitance of the pin combines with the resistor to form an RC circuit, which delays from reaching the appropriate level.) Thus, the resistor can actually cause the processor to never start properly. So in this case, it's better to leave it out.