GICD_CLRSPI_NSR, Clear Non-secure SPI Pending Register
The GICD_CLRSPI_NSR characteristics are:
Removes the pending state from a valid SPI if permitted by the Security state of the access and the GICD_NSACR<n> value for that SPI.
A write to this register changes the state of a pending SPI to inactive, and the state of an active and pending SPI to active.
If GICD_TYPER.MBIS == 0, this register is reserved.
When GICD_CTLR.DS==1, this register provides functionality for all SPIs.
GICD_CLRSPI_NSR is a 32-bit register.
The GICD_CLRSPI_NSR bit assignments are:
INTID, bits [12:0]
The INTID of the SPI.
The function of this register depends on whether the targeted SPI is configured to be an edge-triggered or level-sensitive interrupt:
- For an edge-triggered interrupt, a write to GICD_SETSPI_NSR or GICD_SETSPI_SR adds the pending state to the targeted interrupt. It will stop being pending on activation, or if the pending state is removed by a write to GICD_CLRSPI_NSR, GICD_CLRSPI_SR, or GICD_ICPENDR<n>.
- For a level-sensitive interrupt, a write to GICD_SETSPI_NSR or GICD_SETSPI_SR adds the pending state to the targeted interrupt. It will remain pending until it is deasserted by a write to GICD_CLRSPI_NSR or GICD_CLRSPI_SR. If the interrupt is activated between having the pending state added and being deactivated, then the interrupt will be active and pending.
Accessing the GICD_CLRSPI_NSR
Writes to this register have no effect if:
- The value written specifies a Secure SPI, the value is written by a Non-secure access, and the value of the corresponding GICD_NSACR<n> register is less than 0b10.
- The value written specifies an invalid SPI.
- The SPI is not pending.
16-bit accesses to bits [15:0] of this register must be supported.
A Secure access to this register can clear the pending state of any valid SPI.
GICD_CLRSPI_NSR can be accessed through the memory-mapped interfaces:
This interface is accessible as follows:
- When GICD_CTLR.DS == 0b0 access to this register is WO.
- When IsAccessSecure() access to this register is WO.
- When !IsAccessSecure() access to this register is WO.