USB suspend mode

[georges_emmanuel]

Posted on August 16, 2006 at 14:58

USB suspend mode

[georges_emmanuel]

Posted on August 11, 2006 at 14:42

Hi all,

do you know if there's an issue, i just would like to respect USB standard during suspend mode and draw less than 500µA.

So in ''usb_pwr.c'' (in Suspend() and Resume()) I can handle power management and clock source .

I would like to stop external oscillator by gpio, go in low power mode (ie. LPWFI or STOP) without RTC 32kHz quartz on board (maybe I should add it), and I would like to be wakeup by USB (XTI line 1).

I wonder what does it mean the Free Running Pll, but it seems to be my last chance (see attached picture).

Although there is no FreeRunningClock in SlowClock_Typedef:

void LPWFI(SlowClock_Typedef clock,FunctionalState VRstate)

in advance thx.

________________

Attachments :

an2100page10.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HtTE&d=%2Fa%2F0X0000000aQQ%2F2XFBVMt_L4pykeUn2.awJElmLQFvgXPfhGeqDQ_qzVU&asPdf=false

[georges_emmanuel]

Posted on August 16, 2006 at 14:58

I found in last release of USB lib. some info, but not sure of it.

In USB_PWR.c during suspend a function call to Enter_LowPowerMode

and during resume_init a function call to Leave_LowPowerMode.

I've tried it but nothing happened, the micro don't got any clock.

void Enter_LowPowerMode(void)

{

/* RCCU->CCR |= RCCU_CKAF_SEL_Mask;

RCCU->CFR &=~0x1; //PLL not sys clock

RCCU->PLL1CR &=~0x80; //Free running off

GPIO_Config(GPIO0,0x4010,GPIO_OUT_PP);

GPIO_Config(GPIO1,0x8400,GPIO_OUT_PP);

GPIO_WordWrite(GPIO0,0x0);

FLASHR->CR0|=0x8000; //disable the flash during the LPWFI

PCU->PWRCR |=0x8000; //disable MVR during WFI mode

PCU->PWRCR |=0x0010;

RCCU->CCR |=0x2; //select the 32KHz as peripherl clock during LPWFI

RCCU->CCR |=0x1;

GPIO_Config (GPIO0, 0x1000,GPIO_HI_AIN_TRI); //Disable External oscillator P0.12

RCCU->SMR &=0xFE; // enter LPWFI*/

}

void Leave_LowPowerMode(void)

{

/* GPIO_BitWrite(GPIO0,12,0); */ /*Enable External oscillator*/

/* GPIO_Config(GPIO0,0x1000,GPIO_OUT_PP);

Set_System();

Set_USBClock();*/

}