AnsweredAssumed Answered

LS1043A, Reset Configuration Pin Driving method

Question asked by Logesh S on Mar 1, 2017
Latest reply on Mar 1, 2017 by Serguei Podiatchev

Hi,

 

In LS1043A, For RCW source select we are using nor 16- flash, hence cfg_rcw_src value is 0_0010_0101. This bits corresponds to IFC_AD[8:15], IFC_CLE. The Pin description of these pins is given as below,

 

"This pin is a reset configuration pin. It has a weak (~20 kΩ) internal pull-up P-FET that
is enabled only when the processor is in its reset state. This pull-up is designed such that
it can be overpowered by an external 4.7 kΩ resistor. However, if the signal is intended to
be high after reset, and if there is any device on the net that might pull down the value of
the net at reset, a pull-up or active driver is needed."

 

We are selecting Boot Configuration pins through a pull up or pull down resistors. Say suppose as per above setting of IFC_AD[8:15], IFC_CLE lines as 0_0010_0101 we connected IFC_AD8, IFC_AD9, IFC_AD10, IFC_AD12, IFC_AD13, IFC_AD15 to a pulled down resistor(4.7Kohms) for selecting 16-Bit NOR Flash. 

 

As per pin recommendation do we need to have active driver for normal operation of IFC BUS or it can handle by itself?

 

 

Outcomes