Table of Contents

FIFO()

FIFO() outputs the first stored 16-bit data first.

FIFO command operation flow

bool FIFO(uint8_t fifo_id, bool IN, bool OUT, uint16_t input, uint16_t &output, uint8_t size, bool reset = false)

Commands

Command Arguments Return Value Operation
FIFO(fifo_id, IN, OUT, input, output, size, reset) uint8_t fifo_id — Buffer ID
bool IN — Store input on the rising edge
bool OUT — Output on the rising edge
uint16_t input — Word to store
uint16_t &output — Reference variable receiving the output
uint8_t size — Buffer size
bool reset = false — Reset the buffer 		bool Outputs the first stored 16-bit data first.

Example

Send i twice from Serial Monitor to store 10 and 20. Send o twice to read 10 and then 20. Send r to empty the buffer. 

uint16_t nextValue = 10;
uint16_t removedValue = 0;
 
void setup() {
  Serial.begin(115200);
  Serial.println(F("i: store, o: take, r: reset"));
}
 
void loop() {
  if (!Serial.available()) return;
  const char key = Serial.read();
  const bool store = key == 'i';
  const bool take = key == 'o';
  const bool reset = key == 'r';
  if (!store && !take && !reset) return;
 
  const bool ok = FIFO(0, store, take, nextValue, removedValue, 4, reset);  // Store or retrieve a value on the rising edge of IN or OUT.
  FIFO(0, false, false, 0, removedValue, 4);  // Return IN and OUT to OFF so the next key creates a new rising edge.
 
  if (reset) {
    nextValue = 10;
    Serial.println(F("buffer cleared"));
  } else if (!ok) {
    Serial.println(F("buffer full or empty"));
  } else if (store) {
    Serial.print(F("stored: "));
    Serial.println(nextValue);
    nextValue += 10;
  } else {
    Serial.print(F("taken: "));
    Serial.println(removedValue);
  }
}

Pushing to a full buffer or popping from an empty one fails.

Precautions

IN, OUT, CU and CD act on rising edges. Use a unique id for each counter or buffer, and keep size to the required minimum.

Built-in Commands in the Same Category

← Built-in Command List