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rt-thread/bsp/gd32e230k-start/Libraries/CMSIS/GD/GD32E230/Source/system_gd32e230.c

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/*!
\file system_gd32e230.c
\brief CMSIS Cortex-M23 Device Peripheral Access Layer Source File for
GD32E1x0 Device Series
*/
/* Copyright (c) 2012 ARM LIMITED
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of ARM nor the names of its contributors may be used
to endorse or promote products derived from this software without
specific prior written permission.
*
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
---------------------------------------------------------------------------*/
/* This file refers the CMSIS standard, some adjustments are made according to GigaDevice chips */
#include "gd32e230.h"
/* system frequency define */
#define __IRC8M (IRC8M_VALUE) /* internal 8 MHz RC oscillator frequency */
#define __HXTAL (HXTAL_VALUE) /* high speed crystal oscillator frequency */
#define __SYS_OSC_CLK (__IRC8M) /* main oscillator frequency */
#define VECT_TAB_OFFSET (uint32_t)0x00 /* vector table base offset */
/* select a system clock by uncommenting the following line */
//#define __SYSTEM_CLOCK_8M_HXTAL (__HXTAL)
//#define __SYSTEM_CLOCK_8M_IRC8M (__IRC8M)
#define __SYSTEM_CLOCK_72M_PLL_HXTAL (uint32_t)(72000000)
//#define __SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2 (uint32_t)(72000000)
#define SEL_IRC8M 0x00
#define SEL_HXTAL 0x01
#define SEL_PLL 0x02
/* set the system clock frequency and declare the system clock configuration function */
#ifdef __SYSTEM_CLOCK_8M_HXTAL
uint32_t SystemCoreClock = __SYSTEM_CLOCK_8M_HXTAL;
static void system_clock_8m_hxtal(void);
#elif defined (__SYSTEM_CLOCK_72M_PLL_HXTAL)
uint32_t SystemCoreClock = __SYSTEM_CLOCK_72M_PLL_HXTAL;
static void system_clock_72m_hxtal(void);
#elif defined (__SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2)
uint32_t SystemCoreClock = __SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2;
static void system_clock_72m_irc8m(void);
#else
uint32_t SystemCoreClock = __SYSTEM_CLOCK_8M_IRC8M;
static void system_clock_8m_irc8m(void);
#endif /* __SYSTEM_CLOCK_8M_HXTAL */
/* configure the system clock */
static void system_clock_config(void);
/*!
\brief setup the microcontroller system, initialize the system
\param[in] none
\param[out] none
\retval none
*/
void SystemInit (void)
{
/* enable IRC8M */
RCU_CTL0 |= RCU_CTL0_IRC8MEN;
while(0U == (RCU_CTL0 & RCU_CTL0_IRC8MSTB)){
}
/* reset RCU */
RCU_CFG0 &= ~(RCU_CFG0_SCS | RCU_CFG0_AHBPSC | RCU_CFG0_APB1PSC | RCU_CFG0_APB2PSC |\
RCU_CFG0_ADCPSC | RCU_CFG0_CKOUTSEL | RCU_CFG0_CKOUTDIV | RCU_CFG0_PLLDV);
RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLMF4 | RCU_CFG0_PLLDV);
RCU_CTL0 &= ~(RCU_CTL0_HXTALEN | RCU_CTL0_CKMEN | RCU_CTL0_PLLEN | RCU_CTL0_HXTALBPS);
RCU_CFG1 &= ~(RCU_CFG1_PREDV);
RCU_CFG2 &= ~(RCU_CFG2_USART0SEL | RCU_CFG2_ADCSEL);
RCU_CFG2 &= ~RCU_CFG2_IRC28MDIV;
RCU_CFG2 &= ~RCU_CFG2_ADCPSC2;
RCU_CTL1 &= ~RCU_CTL1_IRC28MEN;
RCU_INT = 0x00000000U;
/* configure system clock */
system_clock_config();
#ifdef VECT_TAB_SRAM
nvic_vector_table_set(NVIC_VECTTAB_RAM,VECT_TAB_OFFSET);
#else
nvic_vector_table_set(NVIC_VECTTAB_FLASH,VECT_TAB_OFFSET);
#endif
}
/*!
\brief configure the system clock
\param[in] none
\param[out] none
\retval none
*/
static void system_clock_config(void)
{
#ifdef __SYSTEM_CLOCK_8M_HXTAL
system_clock_8m_hxtal();
#elif defined (__SYSTEM_CLOCK_72M_PLL_HXTAL)
system_clock_72m_hxtal();
#elif defined (__SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2)
system_clock_72m_irc8m();
#elif defined (__SYSTEM_CLOCK_72M_PLL_IRC48M_DIV2)
system_clock_72m_irc48m();
#else
system_clock_8m_irc8m();
#endif /* __SYSTEM_CLOCK_8M_HXTAL */
}
#ifdef __SYSTEM_CLOCK_8M_HXTAL
/*!
\brief configure the system clock to 8M by HXTAL
\param[in] none
\param[out] none
\retval none
*/
static void system_clock_8m_hxtal(void)
{
uint32_t timeout = 0U;
uint32_t stab_flag = 0U;
/* enable HXTAL */
RCU_CTL0 |= RCU_CTL0_HXTALEN;
/* wait until HXTAL is stable or the startup time is longer than HXTAL_STARTUP_TIMEOUT */
do{
timeout++;
stab_flag = (RCU_CTL0 & RCU_CTL0_HXTALSTB);
}
while((0U == stab_flag) && (HXTAL_STARTUP_TIMEOUT != timeout));
/* if fail */
if(0U == (RCU_CTL0 & RCU_CTL0_HXTALSTB)){
while(1){
}
}
/* HXTAL is stable */
/* AHB = SYSCLK */
RCU_CFG0 |= RCU_AHB_CKSYS_DIV1;
/* APB2 = AHB */
RCU_CFG0 |= RCU_APB2_CKAHB_DIV1;
/* APB1 = AHB */
RCU_CFG0 |= RCU_APB1_CKAHB_DIV1;
/* select HXTAL as system clock */
RCU_CFG0 &= ~RCU_CFG0_SCS;
RCU_CFG0 |= RCU_CKSYSSRC_HXTAL;
/* wait until HXTAL is selected as system clock */
while(0U == (RCU_CFG0 & RCU_SCSS_HXTAL)){
}
}
#elif defined (__SYSTEM_CLOCK_72M_PLL_HXTAL)
/*!
\brief configure the system clock to 72M by PLL which selects HXTAL as its clock source
\param[in] none
\param[out] none
\retval none
*/
static void system_clock_72m_hxtal(void)
{
uint32_t timeout = 0U;
uint32_t stab_flag = 0U;
/* enable HXTAL */
RCU_CTL0 |= RCU_CTL0_HXTALEN;
/* wait until HXTAL is stable or the startup time is longer than HXTAL_STARTUP_TIMEOUT */
do{
timeout++;
stab_flag = (RCU_CTL0 & RCU_CTL0_HXTALSTB);
}
while((0U == stab_flag) && (HXTAL_STARTUP_TIMEOUT != timeout));
/* if fail */
if(0U == (RCU_CTL0 & RCU_CTL0_HXTALSTB)){
while(1){
}
}
FMC_WS &= ~FMC_WS_WSCNT;
FMC_WS |= WS_WSCNT_2;
/* HXTAL is stable */
/* AHB = SYSCLK */
RCU_CFG0 |= RCU_AHB_CKSYS_DIV1;
/* APB2 = AHB */
RCU_CFG0 |= RCU_APB2_CKAHB_DIV1;
/* APB1 = AHB */
RCU_CFG0 |= RCU_APB1_CKAHB_DIV1;
/* PLL = HXTAL * 9 = 72 MHz */
RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF | RCU_CFG0_PLLDV);
RCU_CFG0 |= (RCU_PLLSRC_HXTAL | RCU_PLL_MUL9);
/* enable PLL */
RCU_CTL0 |= RCU_CTL0_PLLEN;
/* wait until PLL is stable */
while(0U == (RCU_CTL0 & RCU_CTL0_PLLSTB)){
}
/* select PLL as system clock */
RCU_CFG0 &= ~RCU_CFG0_SCS;
RCU_CFG0 |= RCU_CKSYSSRC_PLL;
/* wait until PLL is selected as system clock */
while(0U == (RCU_CFG0 & RCU_SCSS_PLL)){
}
}
#elif defined (__SYSTEM_CLOCK_72M_PLL_IRC8M_DIV2)
/*!
\brief configure the system clock to 72M by PLL which selects IRC8M/2 as its clock source
\param[in] none
\param[out] none
\retval none
*/
static void system_clock_72m_irc8m(void)
{
uint32_t timeout = 0U;
uint32_t stab_flag = 0U;
/* enable IRC8M */
RCU_CTL0 |= RCU_CTL0_IRC8MEN;
/* wait until IRC8M is stable or the startup time is longer than IRC8M_STARTUP_TIMEOUT */
do{
timeout++;
stab_flag = (RCU_CTL0 & RCU_CTL0_IRC8MSTB);
}
while((0U == stab_flag) && (IRC8M_STARTUP_TIMEOUT != timeout));
/* if fail */
if(0U == (RCU_CTL0 & RCU_CTL0_IRC8MSTB)){
while(1){
}
}
FMC_WS &= ~FMC_WS_WSCNT;
FMC_WS |= WS_WSCNT_2;
/* AHB = SYSCLK */
RCU_CFG0 |= RCU_AHB_CKSYS_DIV1;
/* APB2 = AHB */
RCU_CFG0 |= RCU_APB2_CKAHB_DIV1;
/* APB1 = AHB */
RCU_CFG0 |= RCU_APB1_CKAHB_DIV1;
/* PLL = (IRC8M/2) * 18 = 72 MHz */
RCU_CFG0 &= ~(RCU_CFG0_PLLSEL | RCU_CFG0_PLLMF);
RCU_CFG0 |= (RCU_PLLSRC_IRC8M_DIV2 | RCU_PLL_MUL18);
/* enable PLL */
RCU_CTL0 |= RCU_CTL0_PLLEN;
/* wait until PLL is stable */
while(0U == (RCU_CTL0 & RCU_CTL0_PLLSTB)){
}
/* select PLL as system clock */
RCU_CFG0 &= ~RCU_CFG0_SCS;
RCU_CFG0 |= RCU_CKSYSSRC_PLL;
/* wait until PLL is selected as system clock */
while(0U == (RCU_CFG0 & RCU_SCSS_PLL)){
}
}
#else
/*!
\brief configure the system clock to 8M by IRC8M
\param[in] none
\param[out] none
\retval none
*/
static void system_clock_8m_irc8m(void)
{
/* AHB = SYSCLK */
RCU_CFG0 |= RCU_AHB_CKSYS_DIV1;
/* APB2 = AHB */
RCU_CFG0 |= RCU_APB2_CKAHB_DIV1;
/* APB1 = AHB */
RCU_CFG0 |= RCU_APB1_CKAHB_DIV1;
/* select IRC8M as system clock */
RCU_CFG0 &= ~RCU_CFG0_SCS;
RCU_CFG0 |= RCU_CKSYSSRC_IRC8M;
/* wait until IRC8M is selected as system clock */
while(0U != (RCU_CFG0 & RCU_SCSS_IRC8M)){
}
}
#endif /* __SYSTEM_CLOCK_8M_HXTAL */
/*!
\brief update the SystemCoreClock with current core clock retrieved from cpu registers
\param[in] none
\param[out] none
\retval none
*/
void SystemCoreClockUpdate (void)
{
uint32_t sws = 0U;
uint32_t pllmf = 0U, pllmf4 = 0U, pllsel = 0U, prediv = 0U, idx = 0U, clk_exp = 0U;
/* exponent of AHB clock divider */
const uint8_t ahb_exp[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
sws = GET_BITS(RCU_CFG0, 2, 3);
switch(sws){
/* IRC8M is selected as CK_SYS */
case SEL_IRC8M:
SystemCoreClock = IRC8M_VALUE;
break;
/* HXTAL is selected as CK_SYS */
case SEL_HXTAL:
SystemCoreClock = HXTAL_VALUE;
break;
/* PLL is selected as CK_SYS */
case SEL_PLL:
/* get the value of PLLMF[3:0] */
pllmf = GET_BITS(RCU_CFG0, 18, 21);
pllmf4 = GET_BITS(RCU_CFG0, 27, 27);
/* high 16 bits */
if(1U == pllmf4){
pllmf += 17U;
}else if(15U == pllmf){
pllmf = 16U;
}else{
pllmf += 2U;
}
/* PLL clock source selection, HXTAL or IRC8M/2 */
pllsel = GET_BITS(RCU_CFG0, 16, 16);
if(0U != pllsel){
prediv = (GET_BITS(RCU_CFG1, 0, 3) + 1U);
SystemCoreClock = (HXTAL_VALUE / prediv) * pllmf;
}else{
SystemCoreClock = (IRC8M_VALUE >> 1) * pllmf;
}
break;
/* IRC8M is selected as CK_SYS */
default:
SystemCoreClock = IRC8M_VALUE;
break;
}
/* calculate AHB clock frequency */
idx = GET_BITS(RCU_CFG0, 4, 7);
clk_exp = ahb_exp[idx];
SystemCoreClock >>= clk_exp;
}
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