Pin States With Respect To Reset - NEC µPD72257 Preliminary User's Manual

Graphics controllers
Table of Contents

Advertisement

Chapter 2

2.6 Pin States with Respect to Reset

82
Any reset (external RESET, internal S/W reset SWRESET, Watchdog reset
WDRESET) re-initializes the pin functions to those chosen by the boot mode
function pin option MODE[3:0].
Note that groups of internal pull-up resistors are activated, depending on the
pinout option MODE[3:0].
During and after reset the pins behave as follows:
During reset all
-
input pins are not active
-
all other pins are in Hi-Z state
For a period of four oscillator clocks CLKIN, with its frequency of the
external resonator at XT1/XT2, after reset release
-
all input pins are active
-
all other pins remain in Hi-Z or are internally fixed to high level,
if the pin is equipped with an activated internal pull-up resistor
After four oscillator clocks CLKIN after reset release all pins adopt
their final state, as specified by the boot option MODE[3:0].
Preliminary User's Manual S19203EE1V3UM00
Pin Functions

Advertisement

Table of Contents
loading

This manual is also suitable for:

Μpd72256

Table of Contents