Hi-
I have problem to make my board enumerated after plugging USB connector into Windows PC. Windows shows nothing after a connection. My configuration is like:
OS: MQX 4.1.1
HW: MX20DX128VFM5
Tool: IAR and I-jet
BSP: k20d50m
My costumed board is driven by 8MHz crystal and +5v comes directly from PC USB port. The USB ID detection pin is tied to ground and +5V power is seen on the board after connecting to PC. After calculation my board should supply 48MHz to ARM core.
Code wise, I can see the device stack is initialized OK. However, in code below, I don't see start_app and start_transactions are TRUE.
| | /* call the periodic task function */ | |
| | USB_CDC_Periodic_Task(); | |
| | | |
| | /*check whether enumeration is complete or not */ | |
| | if((start_app==TRUE) && (start_transactions==TRUE)) | |
No sure where to start the investigation, look at the clock init code in bsp_cm.c:
LDD_TError Cpu_SetClockConfiguration(LDD_TClockConfiguration ModeID)
{
if (ModeID > 0x02U) {
return ERR_RANGE; /* Undefined clock configuration requested requested */
}
switch (ModeID) {
case CPU_CLOCK_CONFIG_0:
...
case CPU_CLOCK_CONFIG_1:
...
case CPU_CLOCK_CONFIG_2:
...
}
...
}
Stepping through the clock init code, I see twice of settings are either config_0 and then config_1 (BSP_CLOCK_CONFIGURATION_AUTOTRPM and BSP_CLOCK_CONFIGURATION_DEFAULT?). From there, USB clock prescalers are USBDIV=1 and USBFRAC=0. Is it correct for USB FS?
My operation steps are:
1. connect my board to Windows PC USB port
2. Load code through IAR I-jet
Windows simply doesn't show anything after the step above? Where should I start to look into this issue?
