GICD_SPENDSGIR<n>, SGI Set-Pending Registers, n = 0 - 3

The GICD_SPENDSGIR<n> characteristics are:

Purpose

Adds the pending state to an SGI.

A write to this register changes the state of an inactive SGI to pending, and the state of an active SGI to active and pending.

Configuration

Four SGI set-pending registers are implemented. Each register contains eight set-pending bits for each of four SGIs, for a total of 16 possible SGIs.

In multiprocessor implementations, each PE has a copy of these registers.

Attributes

GICD_SPENDSGIR<n> is a 32-bit register.

Field descriptions

The GICD_SPENDSGIR<n> bit assignments are:

313029282726252423222120191817161514131211109876543210
SGI_set_pending_bits3SGI_set_pending_bits2SGI_set_pending_bits1SGI_set_pending_bits0

SGI_set_pending_bits<x>, bits [8x+7:8x], for x = 3 to 0

Adds the pending state to SGI number 4n + x for the PE corresponding to the bit number written to.

Reads and writes have the following behavior:

SGI_set_pending_bits<x>Meaning
0x00

If read, indicates that the SGI from the corresponding PE is not pending and is not active and pending.

If written, has no effect.

0x01

If read, indicates that the SGI from the corresponding PE is pending or is active and pending.

If written, adds the pending state to the SGI for the corresponding PE.

On a Warm reset, this field resets to 0.

For SGI ID m, generated by processing element C writing to the corresponding GICD_SGIR field, where DIV and MOD are the integer division and modulo operations:

Accessing the GICD_SPENDSGIR<n>

These registers are used only when affinity routing is not enabled. When affinity routing is enabled for the Security state of an interrupt then the bit associated with SGI in that Security state is RES0. An implementation is permitted to make the register RAZ/WI in this case.

A register bit that corresponds to an unimplemented SGI is RAZ/WI.

These registers are byte-accessible.

If the GIC implementation supports two Security states:

GICD_SPENDSGIR<n> can be accessed through the memory-mapped interfaces:

ComponentOffsetInstance
GIC Distributor0x0F20 + (4 * n)GICD_SPENDSGIR<n>

This interface is accessible as follows:




30/09/2020 15:07; ccead0cb9f089f9ceec50268e82aec9e71047211

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