/*
*********************************************************************************************************
*
*                                       LCD Driver via EBI
*
*                                       IAR Development Kits
*                                              on the
*
*                                    M451
*
* Filename      : ebi_sram.c
* Version       : V1.00
* Programmer(s) : Qian Xianghong
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                             INCLUDE FILES
*********************************************************************************************************
*/

#include  "includes.h"

// 初始化引脚
void SRAM_Init()
{
    /* EBI AD0~1 pins on PB.12~13 */
	SYS->PB_H_MFP &= ~(SYS_PB_H_MFP_PB12_MFP_Msk | SYS_PB_H_MFP_PB13_MFP_Msk);
	SYS->PB_H_MFP |= (SYS_PB_H_MFP_PB12_MFP_EBI_AD0 | SYS_PB_H_MFP_PB13_MFP_EBI_AD1);

    /* EBI AD2~3 pins on PC.14~15 */
	SYS->PC_H_MFP &= ~(SYS_PC_H_MFP_PC14_MFP_Msk | SYS_PC_H_MFP_PC15_MFP_Msk);
	SYS->PC_H_MFP |= (SYS_PC_H_MFP_PC14_MFP_EBI_AD2 | SYS_PC_H_MFP_PC15_MFP_EBI_AD3);

    /* EBI AD4~5 pins on PC.6~7 */
	SYS->PC_L_MFP &= ~(SYS_PC_L_MFP_PC6_MFP_Msk | SYS_PC_L_MFP_PC7_MFP_Msk);
	SYS->PC_L_MFP |= (SYS_PC_L_MFP_PC6_MFP_EBI_AD4 | SYS_PC_L_MFP_PC7_MFP_EBI_AD5);

    /* EBI AD6~12 pins on PA.7~1 */
	SYS->PA_L_MFP &= ~(SYS_PA_L_MFP_PA7_MFP_Msk | SYS_PA_L_MFP_PA6_MFP_Msk);
	SYS->PA_L_MFP |= (SYS_PA_L_MFP_PA7_MFP_EBI_AD6 | SYS_PA_L_MFP_PA6_MFP_EBI_AD7);
	SYS->PA_L_MFP &= ~(SYS_PA_L_MFP_PA5_MFP_Msk | SYS_PA_L_MFP_PA4_MFP_Msk);
	SYS->PA_L_MFP |= (SYS_PA_L_MFP_PA5_MFP_EBI_AD8 | SYS_PA_L_MFP_PA4_MFP_EBI_AD9);
	SYS->PA_L_MFP &= ~(SYS_PA_L_MFP_PA3_MFP_Msk | SYS_PA_L_MFP_PA2_MFP_Msk | SYS_PA_L_MFP_PA1_MFP_Msk);
	SYS->PA_L_MFP |= (SYS_PA_L_MFP_PA3_MFP_EBI_AD10 | SYS_PA_L_MFP_PA2_MFP_EBI_AD11 | SYS_PA_L_MFP_PA1_MFP_EBI_AD12);
	
    /* EBI AD13~15 pins on PA.12~14 */
	SYS->PA_H_MFP &= ~(SYS_PA_H_MFP_PA12_MFP_Msk | SYS_PA_H_MFP_PA13_MFP_Msk | SYS_PA_H_MFP_PA14_MFP_Msk);
	SYS->PA_H_MFP |= (SYS_PA_H_MFP_PA12_MFP_EBI_AD13 | SYS_PA_H_MFP_PA13_MFP_EBI_AD14 | SYS_PA_H_MFP_PA14_MFP_EBI_AD15);
	
	/* EBI nWR on PA.10, EBI nRD pin on PA.11 */
    SYS->PA_H_MFP &= ~(SYS_PA_H_MFP_PA10_MFP_Msk | SYS_PA_H_MFP_PA11_MFP_Msk);
    SYS->PA_H_MFP |= (SYS_PA_H_MFP_PA10_MFP_EBI_NWE | SYS_PA_H_MFP_PA11_MFP_EBI_NRE);

    /* EBI ALE pin on PB.6,  EBI NCS pin on PB.7 */
    SYS->PB_L_MFP &= ~(SYS_PB_L_MFP_PB6_MFP_Msk | SYS_PB_L_MFP_PB7_MFP_Msk);
    SYS->PB_L_MFP |= (SYS_PB_L_MFP_PB6_MFP_EBI_ALE | SYS_PB_L_MFP_PB7_MFP_EBI_NCS);

    // 允许外设时钟
    CLK_EnableModuleClock(EBI_MODULE);
}

// 打开设备和允许中断
void SRAM_Open()
{
	// 打开EBI
	EBI_Open(0, EBI_BUSWIDTH_8BIT, EBI_TIMING_VERYFAST, 0, 0);
}

// 分配扩展内存
// 本函数只能在初始代码里调用（如果在任务里调用可能会导致冲突）
void *SRAM_Alloc(uint32_t size)
{
	static uint32_t SRAM_Base = 0;
	void *p = 0;
	
	// 4字节对齐
	if(size % 4)
		size += (4 - size % 4);
	
	// 检查大小
	if(SRAM_Base + size <= SRAM_SIZE)
	{
//		printf("\nAlloced SRAM at 0x%08X size %04X (%d) bytes\n", EBI_BASE_ADDR + SRAM_Base, size, size);
		p = (void *) (EBI_BASE_ADDR + SRAM_Base);
		SRAM_Base += size;
	}
	else
		printf("\n****** Alloc SRAM failed.\n");
	
	return p;
}