update ex02 comments

This commit is contained in:
hugo LAMY
2025-03-06 12:33:32 +01:00
parent 9398b623af
commit 25541d0582

View File

@@ -1,36 +1,36 @@
#include <avr/io.h>
// stringify
#define STRINGIFY_HELPER(x) #x
#define STRINGIFY(x) STRINGIFY_HELPER(x)
#define STRINGIFY_HELPER(x) #x
#define STRINGIFY(x) STRINGIFY_HELPER(x)
// concatenate
#define CONCAT_HELPER(x, y) x ## y
#define CONCAT(x, y) CONCAT_HELPER(x, y)
#define CONCAT_HELPER(x, y) x ## y
#define CONCAT(x, y) CONCAT_HELPER(x, y)
// get argument
#define ARG_1(v1, v2) v1
#define ARG_2(v1, v2) v2
#define GET_PORT(args) ARG_1 args
#define GET_BIT(args) ARG_2 args
#define ARG_1(v1, v2) v1
#define ARG_2(v1, v2) v2
#define GET_PORT(args) ARG_1 args
#define GET_BIT(args) ARG_2 args
// actions on registers
#define SET(register, bit) register |= 1 << bit
#define CLEAR(register, bit) register &= ~(1 << bit)
#define TEST(register, bit) register & 1 << bit
#define TOGGLE(register, bit) register ^= 1 << bit
#define SET(register, bit) register |= 1 << bit
#define CLEAR(register, bit) register &= ~(1 << bit)
#define TEST(register, bit) register & 1 << bit
#define TOGGLE(register, bit) register ^= 1 << bit
// actions on elements
#define SET_ELEM(elem) SET(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define CLEAR_ELEM(elem) CLEAR(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TEST_ELEM(elem) TEST(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_ELEM(elem) TOGGLE(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define MODE_OUTPUT(elem) SET(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define MODE_INPUT(elem) CLEAR(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_PIN(elem) SET(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem))
#define TEST_PIN(elem) (TEST(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem)))
#define IS_PIN_SET(elem) (TEST_PIN(elem) == 0)
#define IS_PIN_CLEAR(elem) (TEST_PIN(elem) == 1)
#define SET_ELEM(elem) SET(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define CLEAR_ELEM(elem) CLEAR(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TEST_ELEM(elem) TEST(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_ELEM(elem) TOGGLE(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define MODE_OUTPUT(elem) SET(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define MODE_INPUT(elem) CLEAR(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_PIN(elem) SET(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem))
#define TEST_PIN(elem) (TEST(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem)))
#define IS_PIN_SET(elem) (TEST_PIN(elem) == 0)
#define IS_PIN_CLEAR(elem) (TEST_PIN(elem) == 1)
// bits
#define D1 0
@@ -76,13 +76,13 @@ int main() {
SET(TCCR1B, WGM12);
SET(TCCR1B, WGM13);
// Table 16-2 : Non-inverting mode, the LED will be ON for DUTY_CYCLE% of the time (CLEAR OC1A on compare match, SET OC1A at BOTTOM)
// Table 16-2 : non-inverting mode, the LED will be ON for DUTY_CYCLE% of the time (CLEAR OC1A on compare match, SET OC1A at BOTTOM)
SET(TCCR1A, COM1A1);
// set the period (compare TOP value)
// Table 16-4 : set the period (compare TOP value)
ICR1 = TIME_MS(PERIOD);
// set the duty cycle to DUTY_CYCLE% of the time
// 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
OCR1A = TIME_MS(DUTY_CYCLE);
// start the timer with the prescaler