Registers

Attention

resistor[ruh_zi_str] : electrical component that implements electrical resistance
register[reh_juh_str] : a memory location within the actual processor that work at very fast speeds

n-ary numbers

• 1 byte = 8 bits = 2^8 = 256 = [7:0]

• 1 B = 8 b

  JP	EN	usable	15	255	255
  2進数	Binary	0,1	0b1111	0b11111111	B11111111
  10進数	Decimal	0,1,2,3,4,5,6,7,8,9	0d15	0d255	255
  16進数	Hexadecimal	0,1,2,3,4,5,6,7,8,9, A,B,C,D,E,F	0xf	0xff	$f

• Ref. 2進数、8進数、10進数、16進数相互変換ツール

Note

1kB = 1 [kilo] byte = 1000 B
1KB = 1 [ke̞ː] byte = 1024 B = 2^10 B = 1KiB = 1 [kibi] byte

1 bps = 1 [bits per second]

pinout

Datasheet

ATtiny1614

5.　I/O Multiplexing and Considerations
5.1 Multiplexed Signals

Pin names are of type Pxn, with x being the PORT instance (A, B) and n the pin number. T``

16 . PORT - I/O Pin Configuration
16.1 Features
General Purpose Input and Output Pins with Individual Configuration:
– Pull-up

16.2 Overview

The I/O pins of the device are controlled by instances of the PORT peripheral registers. Each PORT instance has up to eight I/O pins. The PORTs are named PORTA, PORTB, PORTC, etc.

Each PORT pin has a corresponding bit in the Data Direction (PORTx.DIR) and Data Output Value (PORTx.OUT) registers to enable that pin as an output and to define the output state. For example, pin PA3 is controlled by DIR[3] and OUT[3] of the PORTA instance.

16.4 Register Summary - PORTx

16.5.1 Data Direction

Name: DIR
This bit field controls the output driver for each PORTx pin.

Value	Description
0	Pxn is configured as an input-only pin, and the output driver is disabled
1	Pxn is configured as an output pin, and the output driver is enabled

16.5.5 Output Value

Name: OUT
This bit field controls the output driver level for each PORTx pin.

Value	Description
0	The pin n (Pxn) output is driven low
1	The Pxn output is driven high

16.5.9 Input Value

Name: IN
This bit field shows the state of the PORTx pins when the digital input buffer is enabled

Value	Description
0	The voltage level on Pxn is low
1	The voltage level on Pxn is high

Program

Arduio Sketch

void setup() {
  pinMode(8, OUTPUT);
}
void loop() {
  digitalWrite(8,HIGH);
  delay(500);
  digitalWrite(8,LOW);
  delay(500);
}

AVR 1-series (1614)

void setup() {
  PORTA.DIR |= 0b00000001;//ポートAの0番ピン(Arduinoの11番ピン)をOUTPUT
}
void loop() {
  PORTA.OUT |= 0b00000001;//ポートAの0番ピン(Arduinoの11番ピン)をHIGH
  delay(500);
  PORTA.OUT &= ~0b00000001;//ポートAの0番ピン(Arduinoの11番ピン)をLOW
  delay(500);
}

AVR

void setup() {
  DDRB |= 0b00000001;//ポートBの0番ピン(Arduinoのn番ピン)をOUTPUT
}
void loop() {
  PORTB |= 0b00000001;//ポートBの0番ピン(Arduinoのn番ピン)をHIGH
  delay(500);
  PORTB &= ~0b00000001;//ポートBの0番ピン(Arduinoのn番ピン)をLOW
  delay(500);
}

Ref. Arduinoで入出力を高速化する方法

Hint

代入
a = 0; //初期値 代入
b = a + 1; //代入
a = a + 1; //加算代入
a += a; //加算代入

OR
PORTB.DIR = 0b00000001; //初期値
PORTB.DIR = PORTB.DIR | 0b00010000 //OR
PORTB.DIR |= 0b00010000 //OR

<!- DDRB = 0b000000; //初期値
DDRB = DDRB | 0b00000001; //OR
DDRB |= 0b00000001; //OR
->

Bitwise Operators (bit演算子)

機能	演算子	使用例
OR	|	指定bitのセット
AND	&	指定bitの取り出し, NOTと併用した指定bitのクリア
XOR	^	bit反転
NOT	~	bit反転, bitクリア
ビットシフト(右)	>>	ビットシフト
ビットシフト(左)	<<	ビットシフト

Note

operand: 被演算子

OR

0  0  1  1    operand1
0  1  0  1    operand2
----------
0  1  1  1    (operand1 | operand2) - returned result

1に指定したbitは、元が0でも1でも、1になる -> 指定bitのセット

NOT

0  1    operand1
-----
1  0   ~operand1

1に指定したbitは、0に反転する (0は1に反転する)

AND

0  0  1  1    operand1
0  1  0  1    operand2
----------
0  0  0  1    (operand1 & operand2) - returned result

0に指定してNOTで反転したbitは、元が0でも1でも、0になる -> 指定bitのクリア

See example below

ref. Arduino Language Reference

Example

void setup() {
  PORTA.DIR |= 0b00010001; //Set PA4 and PA0 to OUTPUT
}

void loop() {
  PORTA.OUT |= 0b00000001;  //Set PA0 to HIGH...(1)
  delay(500);
  PORTA.OUT |= 0b00010000;  //Set PA4 to HIGH...(2)
  delay(500);
  PORTA.OUT &= ~0b00000001; //Set PA0 to LOW ( Remaining PA4 setting )....(3)
}

What to work in (1)(2)(3)

(1) OR
0000 0000   operand1_1
0000 0001   operand1_2
---------
0000 0001   (operand1_1 | operand1_2) - returned result1

(2) OR
0000 0001   operand2_1 (returned result1)
0001 0000   operand2_2
---------
0001 0001   (operand2_1 | operand2_2) - returned result2

(3)
(3-1) NOT
0000 0001   operand3_1
---------
1111 1110   ~operand3_1

(3-2) AND
0001 0001   operand3_2 (returned result2)
1111 1110   ~operand3_1
---------
0001 0000   (operand3_2 & ~operand3_1) - returned result3

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Last update: May 14, 2022