src/machine/machine_stm32l4x6.go


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36

//go:build stm32l4x6

package machine

// Peripheral abstraction layer for the stm32l4x6

func CPUFrequency() uint32 {
	return 80e6
}

// Internal use: configured speed of the APB1 and APB2 timers, this should be kept
// in sync with any changes to runtime package which configures the oscillators
// and clock frequencies
const APB1_TIM_FREQ = 80e6 // 80MHz
const APB2_TIM_FREQ = 80e6 // 80MHz

//---------- I2C related code

// Gets the value for TIMINGR register
func (i2c *I2C) getFreqRange(br uint32) uint32 {
	// This is a 'magic' value calculated by STM32CubeMX
	// for 80MHz PCLK1.
	// TODO: Do calculations based on PCLK1
	switch br {
	case 10 * KHz:
		return 0xF010F3FE
	case 100 * KHz:
		return 0x10909CEC
	case 400 * KHz:
		return 0x00702991
	case 500 * KHz:
		return 0x00300E84
	default:
		return 0
	}
}