Lpc2000

Hello philipsapps (Tom),

I have had some (a LOT) of stability issues with the Keil examples, 
and I was about to incorporate the changes you outlined below. The 
WRCmd, WrCmdDat and rdCmdDat are easy enough to change in the Keil 
samples, however the USB_INT is not like the "original code" you 
show below. The versions on keil.com is 1.00 and you mention v 
1.04 ?? Any idea as to what must be changed in USB_ISR in the 
current 1.00 (which is the only one available from keil at the 
moment)

Regards,
Carsten

--- In lpc2000@yahoogroups.com, "philips_apps" <philips_apps@...> 
wrote:
>
> Lately, I have been scratching my head to get the LPC2148 USB 
> device pass the USBCV test downloaded from "http://www.usb.org".
> 
> Using latest Keil's USB MSC sample, v1.04, the enumeration test 
> will fail from time to time, and program would spin in the 
> WrCmd() or WrCmdDat() routine forever.
> 
> While I was looking into the WrCmd(), WrCmdDat() and RdCmdDat()
> routine and ISR carefully, Keil just found one problem that could
> screw up the USB protocol engine.
> 
> In the USB device block, the registers are located in the VPB
> clock domain, which requires minimum 18Mhz PCLK. in the original 
> MSC example, PCLK uses the default value 1/4 of CCLK = 15Mhz in
> the startup.s. That has probably caused most of the intermitten 
> problems in these Wr/RdCmdDat() modules. The PCLK should be set
> to >= 18Mhz.
> 
> I think that Keil will release a new version of these
> example based on the fixes soon. I am just glad that I am 
> finally able to use the latest fixes to pass all the compliance
> test. So, I pass around to those who had problems with the
> LPC2148 USB driver:
> 
>    Do the following steps:
>    (1) in startup.s, set: 
>     VPBDIV_SETUP    EQU     1
>     VPBDIV_Val      EQU     0x00000001 ; PCLK is set to CCLK 60Mhz
> 
>    (2) In usbhw.c, modify these modules, WrCmd(), WrCmdDat(), 
> and RdCmdDat() as below:
> 
> /*
>  *  Write Command
>  *    Parameters:      cmd:   Command
>  *    Return Value:    None
>  */
> 
> void WrCmd (DWORD cmd) {
> 
>   DEV_INT_CLR = CCEMTY_INT;
>   CMD_CODE = cmd;
>   while ((DEV_INT_STAT & CCEMTY_INT) == 0);
> }
> 
> /*
>  *  Write Command Data
>  *    Parameters:      cmd:   Command
>  *                     val:   Data
>  *    Return Value:    None
>  */
> 
> void WrCmdDat (DWORD cmd, DWORD val) {
> 
>   DEV_INT_CLR = CCEMTY_INT;
>   CMD_CODE = cmd;
>   while ((DEV_INT_STAT & CCEMTY_INT) == 0);
>   DEV_INT_CLR = CCEMTY_INT;
>   CMD_CODE = val;
>   while ((DEV_INT_STAT & CCEMTY_INT) == 0);
> }
> 
> /*
>  *  Read Command Data
>  *    Parameters:      cmd:   Command
>  *    Return Value:    Data Value
>  */
> 
> DWORD RdCmdDat (DWORD cmd) {
> 
>   DEV_INT_CLR = CCEMTY_INT | CDFULL_INT;
>   CMD_CODE = cmd;
>   while ((DEV_INT_STAT & CDFULL_INT) == 0);
>   return (CMD_DATA);
> }
> 
>     (3) in usbhw.c, in the interrupt handler, USB_ISR(), 
> comment out "DEV_INT_CLR = CDFULL_INT;" as seen below:
>           ...
>           EP_INT_CLR = 1 << n;
>           while ((DEV_INT_STAT & CDFULL_INT) == 0);
>           val = CMD_DATA;
> //          DEV_INT_CLR = CDFULL_INT;
> 
>           if ((n & 1) == 0) {              /* OUT Endpoint */
>             if (n == 0) {                  /* Control OUT Endpoint 
*/
>               if (val & EP_SEL_STP) {      /* Setup Packet */
>                 if (USB_P_EP[0]) {
>                   USB_P_EP[0](USB_EVT_SETUP);
>                   continue;
>                 }
>               }
>             }
> 
> That will probably address many intermitten problems seen in the
> past. Meanwhile, we are working hard to improve our documentation
> in the USB chapter.
> 
> Regards,
> 
> Tom
> 
>