Microchip Technology TB3287 Referenzhandbuch

TB3287

Getting Started with Multi-Voltage I/O (MVIO)

Introduction

Authors: Johan Vaarlid, Microchip Technology Inc.

The AVR® DB Family of microcontrollers is equipped with a configurable integrated level shifter. The Multi-Voltage I/O

(MVIO) feature allows a subset of the I/O pins to be powered by a different I/O voltage domain VDDIO2. The rest of

the I/O pins runs on VDD. Both VDD and VDDIO2 have the same voltage range. Consult the Electrical

Characteristics section of the data sheet for the exact voltage range. This eliminates the need of having external level

shifters for communication or control of external components running on a different voltage level. Eliminating external

logic level shifters will, in turn, reduce the BOM and free up PCB real estate.

Figure 1. Multi-Voltage I/O can Completely Replace External Logic Level Converters

VDD

1.8-5.5V

VDD VDD VDDIO2

GND GND GND

GNDGND

VDDIO2

1.8-5.5V

Microcontroller

Logic

Level

Converter

Sensor

MVIO

Sensor

This technical brief describes how the Multi-Voltage I/O feature works on the AVR DB Family of microcontrollers. It

covers the following use cases:

•Polling VDDIO2 Status:

Checking if the VDDIO2 voltage is within the acceptable range by reading the Status bit.

•Interrupt on VDDIO2 Status:

Make use of the interrupt that occurs when the Status bit changes state.

•Measuring VDDIO2:

Use the internal ADC to measure the VDDIO2 voltage.

•Blink a 3V LED with VDD at 1.8V:

A basic example of MVIO blinking an LED with a forward voltage higher than VDD.

Note: The code examples were developed on AVR128DB48 Curiosity Nano (EV35L43A), and are available on

GitHub.

TB3287

Table of Contents

Introduction.....................................................................................................................................................1

1. Relevant Devices.................................................................................................................................... 4

2. Overview................................................................................................................................................. 5

3. Hardware Configuration.......................................................................................................................... 7

3.1. Using the Curiosity Nano AVR128DB48...................................................................................... 7

3.2. Supplying Power To VDDIO2....................................................................................................... 7

4. Reading the Status Bit............................................................................................................................ 9

5. Interrupt on VDDIO2 Status ................................................................................................................. 10

6. Measuring VDDIO2............................................................................................................................... 11

7. Blinking a 3V LED with VDD at 1.8V.....................................................................................................15

8. References............................................................................................................................................17

9. Revision History.................................................................................................................................... 18

10. Appendix............................................................................................................................................... 19

The Microchip Website.................................................................................................................................22

Product Change Notification Service............................................................................................................22

Customer Support........................................................................................................................................ 22

Microchip Devices Code Protection Feature................................................................................................ 22

Legal Notice................................................................................................................................................. 23

Trademarks.................................................................................................................................................. 23

Quality Management System....................................................................................................................... 24

Worldwide Sales and Service.......................................................................................................................25

TB3287

1. Relevant Devices

This section lists the relevant devices for this document. The following figures show the different family devices,

laying out pin count variants and memory sizes:

• Vertical migration upwards is possible without code modification, as these devices are pin-compatible and

provide the same or more features

• Horizontal migration to the left reduces the pin count and, therefore, the available features

• Devices with different Flash memory sizes typically also have different SRAM and EEPROM

Figure 1-1. AVR® DB Family Overview

Pins

Flash

AVR64DB28

AVR128DB28

AVR32DB28

AVR128DB32 AVR128DB48 AVR128DB64

AVR64DB32 AVR64DB48 AVR64DB64

AVR32DB32 AVR32DB48

28 48 64

32 KB

64 KB

128 KB

TB3287

Relevant Devices

2. Overview

The MVIO pins, located on PORTC, are powered by a separate VDDIO2 pin while the rest are powered by VDD. This

allows for additional power domain at a different voltage level within the limits of the Electrical Characteristics of each

device.

Figure 2-1. 48-Pin VQFN/TQFP Pinout Diagram

GND

VDD

PA5

PA6

PA7

PD2

PD3

PD6

PD7

PB0

PD0

PD1

PA2

PA3

PB1

PB2

PB3

PE1

PE2

PE0

PE3

PF0 (XTAL32K1)

PF1 (XTAL32K2)

PA1 (XTALHF2)

PA0 (XTALHF1)

PD5

PA4

PF2

PC0

PC1

PC4

PC5

PC3

PC2

PC6

PC7

PF3

PF4

UPDI

PF5

PF6

VDDIO2

PB4

PB5

GND

AVDD

PD4

Power

Power Supply

Ground

Pin on AVDD Power Domain

Functionality

Programming/Debug

Clock/Crystal

Analog Function

Digital Function OnlyPin on VDD Power Domain

Pin on VDDIO2 Power Domain

These pins are capable of the same digital behavior as regular I/O pins, for example GPIO, serial communication

(USART, SPI, I2C), or connected to PWM peripherals. The input Schmitt Trigger levels are scaled according to the

VDDIO2 voltage, as described in the Electrical Characteristics section of the data sheet.

A configuration fuse determines the MVIO supply mode. The loss or gain of power on VDDIO2 is signaled by a status

A divided-down VDDIO2 voltage is available as input to the ADC.

TB3287

Overview

Figure 2-2. MVIO Block Diagram

VDDIO

VDDIO2

VDD

PORTx[7:0]

PORTy[7:0]

VDDIO2

PORT

VDDIO2S VDDIO2F

Enable

(Int Req.)

ADC Input

Edge Detector

Voltage Divider

Voltage

Monitor

Voltage

Monitor

VDDCORE

TB3287

Overview

3. Hardware Configuration

3.1 Using the Curiosity Nano AVR128DB48

To illustrate the capabilities of Multi-Voltage I/O an AVR128DB48 Curiosity Nano is used. Schematics of the Curiosity

Nano PCB can be found in the References section. To enable MVIO on this development board, perform the below

steps:

1. Remove the resistor right below the VDDIO2 label to disconnect VDDIO2 from VDD. This is resistor R204 in

Figure 3-2.

2. Connect VDDIO2 + to 3.3V of a second power voltage source.

3. Connect VDDIO2 - to GND of a second voltage source.

Refer to the AVR123DB48 Curiosity Nano User Guide for a guide on how to reverse this process.

Any voltage between 1.8V and 5.5V may be applied to VDDIO2, but for the following examples, we will run at 3.3V.

Figure 3-1. AVR128DB48 Curiosity Nano MVIO

123

Figure 3-2. Snippet From the AVR128DB48 Curiosity Nano Schematic

3.2 Supplying Power To VDDIO2

The Multi-Voltage I/O (MVIO) can be configured in one of two supply modes:

TB3287

Hardware Configuration

• Single-Supply mode, where the MVIO-capable I/O pins are powered at the same voltage level as the non-MVIO

capable pins, i.e., VDD. The user must connect the VDDIO2 pin(s) to the VDD pin(s).

• Dual-Supply mode, where the MVIO-capable I/O pins are supplied by the VDDIO2 voltage, which may be

different from the voltage supplied to the VDD pin(s)

Figure 3-3. FUSE.SYSCFG1 - Enabling Dual Supply Mode

8.8.2.5 System Configuration 1

Name: SYSCFG1

Offset: 0x06

Default: 0x08

Property: -

The default value given in this fuse description is the factory-programmed value, and should not be mistaken for the

Reset value.

Bit 7 6 5 4 3 2 1 0

SUT[2:0]

Access R R R R R

Default 0 1 0 0 0

Bits 4:3 – MVSYSCFG[1:0]

This bit field controls the power supply mode.

Value Name Description

0x00 Reserved -

0x02 SINGLE Device used in a single supply configuration.

0x03 Reserved -

MVSYSCFG[1:0]

Device used in a dual supply configuration.DUAL

0x01

TB3287

Hardware Configuration

4. Reading the Status Bit

Before using the MVIO feature, it is recommended to check the VDDIO2 Status (VDDIO2S) bit in the MVIO.STATUS

(Status) register, to make sure that the voltage level of VDDIO2 is within the acceptable range of operation. If this bit

is ‘1’, then VDDIO2 is within the acceptable range of operation.

Figure 4-1. MVIO.STATUS - Reading the Status bit

Bit 7 6 5 4 3 2 1 0

Access R

Reset 0

Bit 0 – VDDIO2S VDDIO2 Status

This bit shows the state of the VDDIO2 voltage level.

Writing to this bit has no effect.

Value Description

0The VDDIO2 supply voltage is below the acceptable range for operation. The MVIO pins are tri-stated.

VDDIO2S

The VDDIO2 supply voltage is within the acceptable range for operation. The MVIO pin configurations

are loaded from the corresponding PORT registers.

//Polling the VDDIO2S bit

if(MVIO.STATUS & MVIO_VDDIO2S_bm)

{

//Do something if VDDIO2 is within acceptable range.

}

TB3287

Reading the Status Bit

5. Interrupt on VDDIO2 Status

When the state of the VDDIO2 Status bit changes, the VDDIO2 interrupt flag will be raised. To be able to catch this

interrupt immediately, it is necessary to enable both the VDDIO2 interrupt and global interrupts in general.

Figure 5-1. MVIO.INTCTRL - Enable the VDDIO2 Interrupt

Bit 7 6 5 4 3 2 1 0

Access R/W

Reset 0

Bit 0 – VDDIO2IE VDDIO2 Interrupt Enable

This bit controls whether the interrupt for a VDDIO2 state change is enabled or not.

Value Description

0The VDDIO2 interrupt is disabled

VDDIO2IE

The VDDIO2 interrupt is enabled

/*Enable the VDDIO2 interrupt*/

MVIO.INTCTRL |= MVIO_VDDIO2IE_bm;

/*Enable Global interrupts*/

sei();

The MVIO vector will be called when the interrupt is triggered. Before returning from the Interrupt Service Routine

(ISR), the VDDIO2 (VDDIO2IF) interrupt flag in the MVIO Interrupt Flags (MVIO.INTFLAGS) register must be cleared.

This is done by writing a ‘1’ to the flag.

Figure 5-2. MVIO.INTFLAGS - Clear VDDIO2 Interrupt Flag

Bit 7 6 5 4 3 2 1 0

Access R/W

Reset 0

Bit 0 – VDDIO2IF VDDIO2 Interrupt Flag

This flag is cleared by writing a ‘1’ to it.

This flag is set when the VDDIO2 Status (VDDIO2S) bit in MVIO.STATUS changes value.

Writing a ‘0’ to this bit has no effect.

Writing a ‘1’ to this bit will clear the VDDIO2 Interrupt Flag.

VDDIO2IF

ISR(MVIO_MVIO_vect)

{

/* The VDDIO2 interrupt has been triggered */

LED0_toggle();

/* Clear the CFD interrupt flag */

MVIO.INTFLAGS |= MVIO_VDDIO2IF_bm;

}

TB3287

Interrupt on VDDIO2 Status

Inhaltsverzeichnis

Andere Microchip Technology Computerhardware Handbücher

Microchip Technology

Microchip Technology MCP6S22 PGA PICtail Bedienungsanleitung

Microchip Technology

Microchip Technology MCP42XX Bedienungsanleitung

Microchip Technology

Microchip Technology WINC1500 Bedienungsanleitung

Microchip Technology

Microchip Technology PIC-BLE Installationshandbuch

Microchip Technology

Microchip Technology dsPIC33 series Bedienungsanleitung

Microchip Technology

Microchip Technology MGC3140 GestIC Bedienungsanleitung

Microchip Technology

Microchip Technology AVR128DA48 Curiosity Nano Installationsanleitung

Microchip Technology

Microchip Technology OLED1 Xplained Pro Bedienungsanleitung

Microchip Technology

Microchip Technology PD-90 G Series Bedienungsanleitung

Microchip Technology

Microchip Technology Photodiode PGAPICtail Bedienungsanleitung

Microchip Technology

Microchip Technology DS61160A Bedienungsanleitung

Microchip Technology

Microchip Technology Adaptec HBA 1100 Bedienungsanleitung

Microchip Technology

Microchip Technology PD-USB-DP60 Bedienungsanleitung

Microchip Technology

Microchip Technology MPLAB REAL ICE In-Circuit Emulator Handbuch

Microchip Technology

Microchip Technology Explorer 16 Bedienungsanleitung

Microchip Technology

Microchip Technology AVR128DB48 Curiosity Nano Installationshandbuch

Microchip Technology

Microchip Technology ATWILC3000 Shield Bedienungsanleitung

Microchip Technology

Microchip Technology DM240316 Bedienungsanleitung

Microchip Technology

Microchip Technology PolarFire MPFS-DISCO-KIT Bedienungsanleitung

Microchip Technology

Microchip Technology VSC8211 Bedienungsanleitung

Microchip Technology

Microchip Technology Multimedia Expansion Board II Bedienungsanleitung

Microchip Technology

Microchip Technology dsPIC33CK Bedienungsanleitung

Microchip Technology

Microchip Technology XMEGA Bedienungsanleitung

Microchip Technology

Microchip Technology RN4870 Bedienungsanleitung

Beliebte Computerhardware Handbücher anderer Marken

EMC2

EMC2 VNX Series Betriebsanleitung

Panasonic

Panasonic DV0PM20105 Bedienungsanleitung

Mitsubishi Electric

Mitsubishi Electric Q81BD-J61BT11 Bedienungsanleitung

Gigabyte

Gigabyte B660M DS3H AX DDR4 Bedienungsanleitung

Raidon

Raidon iT2300 Bedienungsanleitung

National Instruments

National Instruments PXI-8186 Bedienungsanleitung

Hauppauge

Hauppauge WinTV-HVR-2250 Bedienungsanleitung

Kontron

Kontron CP6002 Bedienungsanleitung

Manhattan

Manhattan 702843 Bedienungsanleitung

Aphex

Aphex 230 Bedienungsanleitung

AMD

AMD Phenom II Betriebshandbuch

Intel

Intel NUC 12 Pro Bedienungsanleitung

dbx

dbx Zone Pro 1260 Bedienungsanleitung

Galaxy

Galaxy GHDX2-2430S-24F4D Bedienungsanleitung

Intel

Intel AXXRMFBU4 Bedienungsanleitung

Kontron

Kontron DIMM-PC/MD Bedienungsanleitung

ST X-NUCLEO-SAFEA1B Betriebsanleitung

STEINWAY LYNGDORF

STEINWAY LYNGDORF SP-1 Bedienungsanleitung