Nios® V Processor Reference Manual

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ID 683632
Date 8/01/2022
Public

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Document Table of Contents
Document Table of Contents x
1. Overview 2. Nios® V/m Processor 3. Nios V Processor Reference Manual Archives 4. Document Revision History for the Nios® V Processor Reference Manual
2. Nios® V/m Processor x
2.1. Processor Performance Benchmarks 2.2. Processor Pipeline 2.3. Processor Architecture 2.4. Programming Model 2.5. Core Implementation
2.3. Processor Architecture x
2.3.1. General-Purpose Register File 2.3.2. Arithmetic Logic Unit 2.3.3. Reset and Debug Signals 2.3.4. Control and Status Registers 2.3.5. Exception Controller 2.3.6. Interrupt Controller 2.3.7. Memory and I/O Organization 2.3.8. RISC-V based Debug Module
2.3.6. Interrupt Controller x
2.3.6.1. Timer and Software Interrupt Module
2.3.7. Memory and I/O Organization x
2.3.7.1. Instruction and Data Buses
2.3.7.1. Instruction and Data Buses x
2.3.7.1.1. Instruction Manager Port 2.3.7.1.2. Data Manager Port 2.3.7.1.3. Address Map
2.3.8. RISC-V based Debug Module x
2.3.8.1. Debug Mode 2.3.8.2. Halt from Debug Module 2.3.8.3. Trigger 2.3.8.4. Abstract Commands in Debug Mode 2.3.8.5. Hardware/Software Interface
2.4. Programming Model x
2.4.1. Privilege Levels 2.4.2. Control and Status Registers (CSR) Mapping
2.4.1. Privilege Levels x
2.4.1.1. Machine Mode (M-mode) 2.4.1.2. Debug Mode (D-mode)
2.4.2. Control and Status Registers (CSR) Mapping x
2.4.2.1. Control and Status Register Field
2.5. Core Implementation x
2.5.1. Instruction Set Reference
1. Overview
2. Nios® V/m Processor
3. Nios V Processor Reference Manual Archives
4. Document Revision History for the Nios® V Processor Reference Manual

2.3.3. Reset and Debug Signals

Signal Name Type Description
reset Input This is a global hardware reset signal that forces the Nios® V processor core to reset immediately.
dbg_reset Output
The following are the characteristics of the reset output signal:
  • Visible when you enable the option Enable Debug.
  • Triggered by the GNU debugger (GDB) or niosv-download -r command
  • Internally routed to the Nios® V processor core and timer module. This allows the JTAG debugger to reset the processor and the timer module.
  • Can be connected to the reset input signal of other components as needed.
reset_req Input
  • You can request a reset to the Nios® V processor core by asserting the reset_req signal.
  • The reset_req signal must remain asserted until the processor asserts reset_req_ack signal. Failure for the signal to remain asserted can cause the processor to be in a non-deterministic state.
  • Assertion of the reset_req signal in debug mode has no effect on the processor's state.
reset_req_ack Output
  • The Nios® V processor responds that the reset is successful by asserting the reset_req_ack signal.
  • After the processor is successfully reset, the assertion of the reset_req_ack signal can happen multiple times periodically until the de-assertion of the reset_req signal.
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