Entity: alert_handler_accu
- File: alert_handler_accu.sv
Diagram
Description
Copyright lowRISC contributors. Licensed under the Apache License, Version 2.0, see LICENSE for details. SPDX-License-Identifier: Apache-2.0
This module accumulates incoming alert triggers. Once the current accumulator value is greater or equal the accumulator threshold, the next occurence of class_trig_i will trigger escalation.
Note that the accumulator is implemented using a saturation counter which does not wrap around.
Ports
| Port name | Direction | Type | Description |
|---|---|---|---|
| clk_i | input | ||
| rst_ni | input | ||
| class_en_i | input | class enable | |
| clr_i | input | clear the accumulator | |
| class_trig_i | input | increments the accu | |
| thresh_i | input | [AccuCntDw-1:0] | escalation trigger threshold |
| accu_cnt_o | output | [AccuCntDw-1:0] | output of current accu value |
| accu_trig_o | output | escalation trigger output | |
| accu_fail_o | output | asserted if the tandem accu counters are not equal |
Signals
| Name | Type | Description |
|---|---|---|
| trig_gated_unbuf | logic | |
| accu_q | logic [1:0][AccuCntDw-1:0] | We employ two redundant counters to guard against FI attacks. If any of the two is glitched and the two counter states do not agree, the check_fail_o signal is asserted which will move the corresponding escalation FSM into a terminal error state where all escalation actions will be permanently asserted. |