SC 58x DAI clearing latch register


Hi I am trying to make a couple of DAI for the SC-589 work as falling edge interrupts. 

I have initialized the pin as follows


*pREG_DAI0_IMSK_FE = 1U << 29;    // bit 29 is INT 7

adi_int_InstallHandler(INTR_DAI0_IRQL, (ADI_INT_HANDLER_PTR)ISR_HANDLER ,0 , true);

and  my ISR is 

void TACHOMETER_ISR_HANDLER(int iid, void *handlerArg)
if((*pREG_DAI0_IRPTL_L & 0x20000000)== 0x20000000 )
*pREG_DAI0_IRPTL_L = 0x20000000; // W1C


The *pREG_DAI0_IRPTL_L = 0x20000000; // W1C does not compile.  The HRM says that to perform a W1C

operation to clear the latch.

Digging into further I searched that it is defined under ADSP_SC589_cdef

#define pREG_DAI0_IRPTL_L                ((__I __C  uint32_t  *) REG_DAI0_IRPTL_L)                /*  Low Priority Interrupt Latch Register */

If I search above this file, the attribute ___I is commented to be read only.

Is this the reason, the compiler complains? 

Please advise how to perform the W1C operation for this purpose.  

Thank you in advance for your response.