A4.14
Event communication using WFE or SEV
An external agent can use the
EVENTI
pin to participate in a WFE or SEV event communication with
the Cortex
‑
A35 processor.
When this pin is asserted, it sends an event message to all the cores in the device. This is similar to
executing a
SEV
instruction on one core in the cluster. This enables the external agent to signal to the
cores that it has released a semaphore and that the cores can leave the WFE low-power state. The
EVENTI
input pin must remain HIGH for at least one
CLKIN
clock cycle to be visible by the cores.
The external agent can determine that at least one of the cores in the cluster has executed an
SEV
instruction by checking the
EVENTO
pin. When
SEV
is executed by any of the cores in the cluster, an
event is signaled to all the cores in the device, and the
EVENTO
pin is asserted. This pin is asserted
HIGH for three
CLKIN
clock cycles when any core in the cluster executes an
SEV
instruction.
A4 Power Management
A4.14 Event communication using WFE or SEV
100236_0100_00_en
Copyright © 2015–2017, 2019 Arm Limited or its affiliates. All rights
reserved.
A4-73
Non-Confidential
Summary of Contents for Cortex-A35
Page 4: ......
Page 18: ......
Page 26: ......
Page 27: ...Part A Functional Description ...
Page 28: ......
Page 145: ...Part B Register Descriptions ...
Page 146: ......
Page 573: ...Part C Debug ...
Page 574: ......
Page 845: ...Part D Appendices ...
Page 846: ......