Pad Controller (PADCON)

Introduction

Pads of W7500 are controllable. User can control pad’s characteristic.

Features

• W7500 have digital I/O pads and digital/analog mux I/O pads
• Controllable characteristics of pad are pull-up, pull-down, driving strength, input enable and CMOS/Schmitt trigger input buffer
• Each pad can be control individually by register.

Functional description

The below Figure shows the function schematic of digital I/O pad of W7500.

The below Figure shows the function schematic of digital/analog mux IO pad of W7500

Initials of Pad diagram is same as below.

P - PAD
YA – Analog Input (connect to ADC input)
Y – Digital Input
IE – Input buffer enable

Condition		A	Y	P
Input buffer enable (IE =1)	Output mode	OUT	OUT	OUT
	Input mode	No use	IN	IN
Input buffer enable (IE = 0)	Output mode	OUT	Low(0)	OUT
	Input mode	No use	IN	IN

CS – CMOS/Schmitt trigger input buffer select
PU – Pull-up enable
A – Digital Output
DS – Driving strength select

Condition		Rise/Fall Time(nSec)		Propagation Delay(nSec)
Driving Strength	Capacitance loading	Min	Max	Min	Max
High (DS = 1)	25pF	4	18	7	27
	100pF	11	53	11	44
Low (DS = 0)	25pF	1	8	4	16
	100pF	4	23	7

PD – Pull-down enable

User can set pad condition with IE, CS, PU/PD, DS by register.
And pads are can be controlled individually.