Interrupt Pending (Intpnd) Register - Samsung S3C2416 User Manual

INTERRUPT CONTROLLER

2.4 INTERRUPT PENDING (INTPND) REGISTER

Each of the 32 bits in the interrupt pending register shows whether the corresponding interrupt request, which is
unmasked and waits for the interrupt to be serviced, has the highest priority. Since the INTPND register is located
after the priority logic, only one bit can be set to 1, and that interrupt request generates IRQ to CPU. In interrupt
service routine for IRQ, you can read this register to determine which interrupt source is serviced among the 32
sources.
Like the SRCPND register, this register has to be cleared in the interrupt service routine after clearing the
SRCPND register. We can clear a specific bit of the INTPND register by writing a data to this register. It clears
only the bit positions of the INTPND register corresponding to those set to one in the data. The bit positions
corresponding to those that are set to 0 in the data remains as they are.
Register
INTPND1 0X4A000010
INTPND2 0X4A000050
NOTES:
1. If the FIQ mode interrupt occurs, the corresponding bit of INTPND will not be turned on as the INTPND register is
available only for IRQ mode interrupt.
2. Cautions in clearing the INTPND register. The INTPND register is cleared to "0" by writing "1". If the INTPND bit, which
has "1", is cleared by "0", the INTPND register & INTOFFSET register may have unexpected value in some case.
So, you never write "0" on the INTPND bit having "1". The convenient method to clear the INTPND register is writing the
INTPND register value on the INTPND register. (In even our example code, this guide hasn't been applied yet.)
INTPND1
INT_ADC
INT_RTC
Reserved
INT_UART0
INT_IIC0
INT_USBH
INT_USBD
INT_NAND
INT_UART1
INT_SPI0
INT_SDI0
INT_SDI1
Reserved
10-16
Address R/W
R/W Indicate the interrupt request status for group 1.
0 = The interrupt has not been requested.
1 = The interrupt source has asserted the interrupt
request.
R/W Indicate the interrupt request status for group 2.
0 = The interrupt has not been requested.
1 = The interrupt source has asserted the interrupt
request.
Bit
[31] 0 = Not requested,
[30] 0 = Not requested,
[29] 0 = Not requested,
[28] 0 = Not requested,
[27] 0 = Not requested,
[26] 0 = Not requested,
[25] 0 = Not requested,
[24] 0 = Not requested,
[23] 0 = Not requested,
[22] 0 = Not requested,
[21] 0 = Not requested,
[20] 0 = Not requested,
[19] 0 = Not requested,
S3C2416X RISC MICROPROCESSOR
Description
Description
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
1 = Requested
Reset Value
0x00000000
0x00000000
Initial State
0
0
0
0
0
0
0
0
0
0
0
0
0