Jw32的PLL问题 PLL

bluewind

我用Jw32的USB, 在MMEVS仿真器上没有任何问题, 我们所有电脑都可枚举,但写到芯片上后问题较多, 有的电脑可以枚举,有的则不行,我用USB分析仪发现数据传输错误较多, 有的竟然是CRC出错,非常不稳定,我怀疑PLL不稳定,但我用的PLL电路是DATASHEET上的, EMC我检查问题也不大, 请帮我分析原因, 这里先谢谢了.

wxw816

JW32在MMEVS仿真器和写到芯片上的PLL配置是有区别的，参考下面程序
//====================================================
//for 48MHZ CGMCLK, 8MHZ bus, 4MHz reference clk
// R=1, N=06, P=1, E=2, L=96
//====================================================
void PLL_start(void)
{
PCTL_BCS = 0x0; //1 :Select vco as bus clock ,0: osc as bus clock
PCTL_PLLON = 0x0; //PLL OFF
PCTL = 0x06; //P = 1,E = 2
PMSH = 0x00; //N high = 0
PMSL = 0x06; //N low = 6
PMRS = 0x96; //L = 96
PMDS = 0x01; //R = 1
PBWC_AUTO = 0x1; //Set auto mode
PCTL_PLLON = 0x1; //PLL ON
while (!PBWC_LOCK ){}; // wait for pll lock
#if MMEVS_NODEBUG
PCTL_BCS = 0x1; //1 :Select vco as bus clock ,0: osc as bus clock
#endif
}

strongchen

JW32的晶振范围应该是1～4M。