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//go:build stm32 && stm32l4
// +build stm32,stm32l4
package runtime
import (
"device/stm32"
"machine"
)
const (
PWR_CR1_VOS_0 = 1 << stm32.PWR_CR1_VOS_Pos
PWR_CR1_VOS_1 = 2 << stm32.PWR_CR1_VOS_Pos
PWR_REGULATOR_VOLTAGE_SCALE1 = PWR_CR1_VOS_0
PWR_REGULATOR_VOLTAGE_SCALE2 = PWR_CR1_VOS_1
FLASH_LATENCY_0 = 0
FLASH_LATENCY_1 = 1
FLASH_LATENCY_2 = 2
FLASH_LATENCY_3 = 3
FLASH_LATENCY_4 = 4
RCC_PLLP_DIV2 = 2
RCC_PLLP_DIV7 = 7
RCC_PLLQ_DIV2 = 2
RCC_PLLR_DIV2 = 2
RCC_CFGR_SWS_MSI = 0x0
RCC_CFGR_SWS_PLL = 0xC
RCC_PLLSOURCE_MSI = 1
RCC_PLL_SYSCLK = stm32.RCC_PLLCFGR_PLLREN
)
type arrtype = uint32
func init() {
initCLK()
machine.InitSerial()
initTickTimer(&machine.TIM15)
}
func putchar(c byte) {
machine.Serial.WriteByte(c)
}
func getchar() byte {
for machine.Serial.Buffered() == 0 {
Gosched()
}
v, _ := machine.Serial.ReadByte()
return v
}
func buffered() int {
return machine.Serial.Buffered()
}
func initCLK() {
// PWR_CLK_ENABLE
stm32.RCC.APB1ENR1.SetBits(stm32.RCC_APB1ENR1_PWREN)
_ = stm32.RCC.APB1ENR1.Get()
// Disable Backup domain protection
if !stm32.PWR.CR1.HasBits(stm32.PWR_CR1_DBP) {
stm32.PWR.CR1.SetBits(stm32.PWR_CR1_DBP)
for !stm32.PWR.CR1.HasBits(stm32.PWR_CR1_DBP) {
}
}
// Set LSE Drive to LOW
stm32.RCC.BDCR.ReplaceBits(0, stm32.RCC_BDCR_LSEDRV_Msk, 0)
// Initialize the High-Speed External Oscillator
initOsc()
// PWR_VOLTAGESCALING_CONFIG
stm32.PWR.CR1.ReplaceBits(0, stm32.PWR_CR1_VOS_Msk, 0)
_ = stm32.PWR.CR1.Get()
// Set flash wait states (min 5 latency units) based on clock
if (stm32.FLASH.ACR.Get() & 0xF) < 5 {
stm32.FLASH.ACR.ReplaceBits(5, 0xF, 0)
}
// Ensure HCLK does not exceed max during transition
stm32.RCC.CFGR.ReplaceBits(8<<stm32.RCC_CFGR_HPRE_Pos, stm32.RCC_CFGR_HPRE_Msk, 0)
// Set SYSCLK source and wait
// (3 = RCC_SYSCLKSOURCE_PLLCLK, 2=RCC_CFGR_SWS_Pos)
stm32.RCC.CFGR.ReplaceBits(3, stm32.RCC_CFGR_SW_Msk, 0)
for stm32.RCC.CFGR.Get()&(3<<2) != (3 << 2) {
}
// Set HCLK
// (0 = RCC_SYSCLKSOURCE_PLLCLK)
stm32.RCC.CFGR.ReplaceBits(0, stm32.RCC_CFGR_HPRE_Msk, 0)
// Set flash wait states (max 5 latency units) based on clock
if (stm32.FLASH.ACR.Get() & 0xF) > 5 {
stm32.FLASH.ACR.ReplaceBits(5, 0xF, 0)
}
// Set APB1 and APB2 clocks (0 = DIV1)
stm32.RCC.CFGR.ReplaceBits(0, stm32.RCC_CFGR_PPRE1_Msk, 0)
stm32.RCC.CFGR.ReplaceBits(0, stm32.RCC_CFGR_PPRE2_Msk, 0)
}
func initOsc() {
sysclkSource := stm32.RCC.CFGR.Get() & stm32.RCC_CFGR_SWS_Msk
pllConfig := stm32.RCC.PLLCFGR.Get() & stm32.RCC_PLLCFGR_PLLSRC_Msk
// Enable MSI, adjusting flash latency
if sysclkSource == RCC_CFGR_SWS_MSI ||
(sysclkSource == RCC_CFGR_SWS_PLL && pllConfig == RCC_PLLSOURCE_MSI) {
if MSIRANGE > getMSIRange() {
setFlashLatencyFromMSIRange(MSIRANGE)
setMSIFreq(MSIRANGE, 0)
} else {
setMSIFreq(MSIRANGE, 0)
if sysclkSource == RCC_CFGR_SWS_MSI {
setFlashLatencyFromMSIRange(MSIRANGE)
}
}
} else {
stm32.RCC.CR.SetBits(stm32.RCC_CR_MSION)
for !stm32.RCC.CR.HasBits(stm32.RCC_CR_MSIRDY) {
}
setMSIFreq(MSIRANGE, 0)
}
// Enable LSE, wait until ready
stm32.RCC.BDCR.SetBits(stm32.RCC_BDCR_LSEON)
for !stm32.RCC.BDCR.HasBits(stm32.RCC_BDCR_LSEON) {
}
// Disable the PLL, wait until disabled
stm32.RCC.CR.ClearBits(stm32.RCC_CR_PLLON)
for stm32.RCC.CR.HasBits(stm32.RCC_CR_PLLRDY) {
}
// Configure the PLL
stm32.RCC.PLLCFGR.ReplaceBits(
(1)| // 1 = RCC_PLLSOURCE_MSI
(PLL_M-1)<<stm32.RCC_PLLCFGR_PLLM_Pos|
(PLL_N<<stm32.RCC_PLLCFGR_PLLN_Pos)|
(((PLL_Q>>1)-1)<<stm32.RCC_PLLCFGR_PLLQ_Pos)|
(((PLL_R>>1)-1)<<stm32.RCC_PLLCFGR_PLLR_Pos)|
(PLL_P<<stm32.RCC_PLLCFGR_PLLP_Pos),
stm32.RCC_PLLCFGR_PLLSRC_Msk|stm32.RCC_PLLCFGR_PLLM_Msk|
stm32.RCC_PLLCFGR_PLLN_Msk|stm32.RCC_PLLCFGR_PLLP_Msk|
stm32.RCC_PLLCFGR_PLLR_Msk|stm32.RCC_PLLCFGR_PLLP_Msk,
0)
// Enable the PLL and PLL System Clock Output, wait until ready
stm32.RCC.CR.SetBits(stm32.RCC_CR_PLLON)
stm32.RCC.PLLCFGR.SetBits(stm32.RCC_PLLCFGR_PLLREN) // = RCC_PLL_SYSCLK
for !stm32.RCC.CR.HasBits(stm32.RCC_CR_PLLRDY) {
}
// Enable system clock output
stm32.RCC.PLLCFGR.SetBits(RCC_PLL_SYSCLK)
}
func getMSIRange() uint32 {
if stm32.RCC.CR.HasBits(stm32.RCC_CR_MSIRGSEL) {
return (stm32.RCC.CR.Get() & stm32.RCC_CR_MSIRANGE_Msk) >> stm32.RCC_CR_MSIRANGE_Pos
}
return (stm32.RCC.CSR.Get() & stm32.RCC_CSR_MSISRANGE_Msk) >> stm32.RCC_CSR_MSISRANGE_Pos
}
func setMSIFreq(r uint32, calibration uint32) {
stm32.RCC.CR.SetBits(stm32.RCC_CR_MSIRGSEL)
stm32.RCC.CR.ReplaceBits(r<<stm32.RCC_CR_MSIRANGE_Pos, stm32.RCC_CR_MSIRANGE_Msk, 0)
stm32.RCC.ICSCR.ReplaceBits(calibration<<stm32.RCC_ICSCR_MSITRIM_Pos, stm32.RCC_ICSCR_MSITRIM_Msk, 0)
}
func setFlashLatencyFromMSIRange(r uint32) {
var vos uint32
if pwrIsClkEnabled() {
vos = pwrExGetVoltageRange()
} else {
pwrClkEnable()
vos = pwrExGetVoltageRange()
pwrClkDisable()
}
latency := uint32(FLASH_LATENCY_0)
if vos == PWR_REGULATOR_VOLTAGE_SCALE1 {
if r > stm32.RCC_CR_MSIRANGE_Range16M {
if r > stm32.RCC_CR_MSIRANGE_Range32M {
latency = FLASH_LATENCY_2
} else {
latency = FLASH_LATENCY_1
}
}
} else if r > stm32.RCC_CR_MSIRANGE_Range16M {
latency = FLASH_LATENCY_3
} else {
if r == stm32.RCC_CR_MSIRANGE_Range16M {
latency = FLASH_LATENCY_2
} else if r == stm32.RCC_CR_MSIRANGE_Range8M {
latency = FLASH_LATENCY_1
}
}
stm32.FLASH.ACR.ReplaceBits(latency, stm32.Flash_ACR_LATENCY_Msk, 0)
}
func pwrIsClkEnabled() bool {
return stm32.RCC.APB1ENR1.HasBits(stm32.RCC_APB1ENR1_PWREN)
}
func pwrClkEnable() {
stm32.RCC.APB1ENR1.SetBits(stm32.RCC_APB1ENR1_PWREN)
}
func pwrClkDisable() {
stm32.RCC.APB1ENR1.ClearBits(stm32.RCC_APB1ENR1_PWREN)
}
func pwrExGetVoltageRange() uint32 {
return stm32.PWR.CR1.Get() & stm32.PWR_CR1_VOS_Msk
}
|
