gc80c510 CORERIVER Semiconductor, gc80c510 Datasheet - Page 36

• Manufacturer Part Number: gc80c510
• Description: Eprom/rom 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

P1[0] and P1[1] is OFF. To enable the pull-up resistor control, set to the bit of the P1SEL register to “0”
(0 = Pull-up ON, 1=Pull-up OFF (Default)). Note that P1[2] has no pull-up.
[How to control the P1 output type]
of P1[0] and P1[1] is push-pull output type. To configure the bit output type of the P1[0] and P1[1] to
open-drain output, set the bit of the P1TYPE register to “1” (0 = Push-pull output (Default), 1 = Open-
drain output). Note that P1[2] is only open-drain output type. If user wants to use the P1[2] pin as output
pin, this pin may need the external pull-up resistor.
several other SFRs
[About the alternative pins and description]
The initial value of P1TYPE (Port 1 Type Control) register is ******00h. This means that the output type
In addition, all the pins have an alternative function listed below. Each of the functions is controlled by
Alternative Pin
Port 1
RESETB
XTAL1
XTAL2
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External Crystal Oscillator Input. (Refer to ALTSEL)
External Crystal Oscillator Output. (Refer to ALTSEL)
Inverted Reset Input. Active Low. (Refer to ALTSEL)
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Description
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RESETB
P1[2]
Functional Description
XTAL2
P1[1]
XTAL1
P1[0]