请问各位高手,晶振由11.0592M改为20M,改为如下后上电不运行。
config.h
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#define Fosc 20000000 // 由11059200
#define Fcclk (Fosc * 1)
#define Fcco (Fcclk * 2)
#define Fpclk (Fcclk / 4) * 1
target.c 这个文件不要改吧
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// 设置系统各部分时钟
// Set system timers for each component
PLLCON = 1; // 设置激活但未连接PLL
// 设置外设(VPB时钟pclk)时钟与系统(cclk)时钟的分频比
#if (Fpclk / (Fcclk / 2)) == 1
VPBDIV = 0;
#endif
#if (Fpclk / (Fcclk / 2)) == 2
VPBDIV = 2;
#endif
#if (Fpclk / (Fcclk / 2)) == 4
VPBDIV = 1;
#endif
// 设定PLL的乘因子M和除因子P的值
#if (Fcco / Fcclk) == 2
PLLCFG = ((Fcclk / Fosc) - 1) | (0 << 5);
#endif
#if (Fcco / Fcclk) == 4
PLLCFG = ((Fcclk / Fosc) - 1) | (1 << 5);
#endif
#if (Fcco / Fcclk) == 8
PLLCFG = ((Fcclk / Fosc) - 1) | (2 << 5);
#endif
#if (Fcco / Fcclk) == 16
PLLCFG = ((Fcclk / Fosc) - 1) | (3 << 5);
#endif
PLLFEED = 0xaa;
PLLFEED = 0x55;
while((PLLSTAT & (1 << 10)) == 0); // 等待锁定
PLLCON = 3; // 设置激活并连接PLL
PLLFEED = 0xaa; // 发送PLL馈送序列,执行激活和
连接动作.
PLLFEED = 0x55;
// 设置存储器加速模块
/* Set memory accelerater module*/
MAMCR = 0;
#if Fcclk < 20000000
MAMTIM = 1;
#else
#if Fcclk < 40000000
MAMTIM = 2;
#else
MAMTIM = 3;
#endif
#endif
MAMCR = 2; |
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