Eccelerators.RiscV

src/Contracts/IRvExecutionUnit.lvt

namespace Eccelerators.RiscV.Contracts

/**
 * One outstanding blocking call, exclusive controlling caller. Completion is
 * return, not a fixed number of clocks. All outputs assigned even on fault.
 * fault=false makes cause/tval zero; fault=true suppresses result/redirect.
 * No register, PC, memory or peripheral writes by this arithmetic/control unit.
 * Reset is legal only after completion; there is no cancellation or flush API.
 */
public interface IRvExecutionUnit
{
	/**
	 * Resets unit-local state after any prior Execute call has completed.
	 * The exclusive caller must quiesce execution first; no cancellation is provided.
	 */
	fn Reset()

	/**
	 * Executes the composition-defined operation using two operands and original PC.
	 * Returns only after completion; latency may vary. Overwrites every output.
	 * Success returns value and optional redirect/target, with zero cause/tval.
	 * Fault returns cause/tval, zero value/target and no redirect.
	 * Never writes architectural registers, PC, memory or peripherals.
	 */
	fn Execute(operation: uint, left: uint, right: uint, pc: uint,
		value: out uint, redirect: out bool, target: out uint,
		fault: out bool, cause: out uint, tval: out uint)
}