WWDT in LPC811 not work correctly

[lpcware]

Content originally posted in LPCWare by MICHALKO12 on Mon May 11 04:46:42 MST 2015
WWDT in LPC811 not work correctly. Feed causes the counter stop and reset the processor.

static void
InitWDT( void )
{
volatile uint32_t x;
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<17);
LPC_SYSCON->PDRUNCFG &= ~( 1<<6 );
LPC_SYSCON->WDTOSCCTRL = (1<<5) | 0x1F;// 0,6MHZ/64 = ~9,3kHz (±40%)
LPC_WWDT->TC = ((uint32_t)( WDT_CLK / 4 * WDT_TIMEOUT ));
LPC_WWDT->WARNINT = ((uint32_t) (WDT_CLK / 4 * WDT_WARNING ));
//LPC_WWDT->WINDOW = ((uint32_t) (WDT_CLK / 4 * WDT_TIMEOUT ));
LPC_WWDT->MOD = 0b111001;
for( x = 0; x < 1000; x++);
LPC_WWDT->FEED = 0xAA;
LPC_WWDT->FEED = 0x55;
LPC_WWDT->MOD = 0b111001;
//NVIC_EnableIRQ(WDT_IRQn);
}

void
WWDTFeed( void )
{
uint32_t primask  = __get_PRIMASK();

__disable_irq();
LPC_WWDT->FEED = 0xAA;
LPC_WWDT->FEED = 0x55;
__set_PRIMASK( primask );
}


void ResetWWDT( void )     // Called every 1s from main()
{
static uint32_t cnt = 0;
UsartPutHex32(LPC_WWDT->MOD);
UsartPutChar( ' ' );
UsartPutHex32(LPC_WWDT->TV);
UsartPutChar( ' ' );
if( ++cnt > 3 )
{
cnt = 0;
WWDTFeed();
}

UsartPutHex32(LPC_WWDT->MOD);
UsartPutChar( ' ' );
UsartPutHex32(LPC_WWDT->TC);
UsartPutChar( ' ' );
UsartPutHex32(LPC_WWDT->TV);
UsartPutChar( ' ' );
UsartPutHex32(LPC_WWDT->WARNINT);
UsartPutChar( ' ' );
UsartPutHex32(LPC_WWDT->WINDOW);
UsartPutChar( ' ' );
UsartPutHex32(LPC_SYSCON->SYSRSTSTAT);
LPC_SYSCON->SYSRSTSTAT = 0x1f;
UsartSendString(_eol);
}

Log file:

   MOD      TV      MOD      TC        TV     WARNINT  WINDOW  SYSRSTSTAT
00000031 00007F2B 00000031 0000883B 00007F26 0000019F 00FFFFFF 00000001
00000031 0000761A 00000031 0000883B 00007615 0000019F 00FFFFFF 00000000
00000031 00006D09 00000031 0000883B 00006D04 0000019F 00FFFFFF 00000000
00000031 000063F8 00000031 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000
0000003C 000063F4 0000003C 0000883B 000063F4 0000019F 00FFFFFF 00000000

[lpcware]

Content originally posted in LPCWare by MICHALKO12 on Tue May 19 15:30:43 MST 2015
[u]Hi nerd herd[/u]

Of course, since the user manual is an error regarding the clearing interrupt flag

User manual Rev. 1.4 — 7 February 2014

---

Quote:
WDINT The Watchdog interrupt flag is set when the Watchdog counter reaches the value
specified by WARNINT. This flag is cleared when any reset occurs, and is cleared by
software by writing a 0 to this bit.

---

wwdt_8xx.c

/* Clear WWDT interrupt status flags */
void Chip_WWDT_ClearStatusFlag(LPC_WWDT_T *pWWDT, uint32_t status)
{
if (status & WWDT_WDMOD_WDTOF) {
pWWDT->MOD &= (~WWDT_WDMOD_WDTOF) & WWDT_WDMOD_BITMASK;
}

if (status & WWDT_WDMOD_WDINT) {
pWWDT->MOD |= WWDT_WDMOD_WDINT;      // <---------------------------------------------------------- 
}
}

Additionally, you can stop WWDT counter clearing the WDEN bit in the MOD register. Why?

Regards,
Michalko12.

[lpcware]

Content originally posted in LPCWare by nerd herd on Tue May 19 13:15:08 MST 2015
Hi MICHALKO12,

Have you tried looking at the LPCOpen periph_wwdt example for reference?

http://www.lpcware.com/content/nxpfile/lpcopen-software-development-platform-lpc8xx-packages