OPINION

delivered the opinion of the Court in which

After the trial judge denied his motion to suppress methamphetamine found during a traffic stop, appellant pled guilty to its possession pursuant to a plea bargain. He then appealed the trial judge’s suppression ruling. The court of appeals reversed, finding that the officer lacked reasonable suspicion to continue to detain appellant until a drug dog was brought to the scene.1 The court also declined to address what it called a “cross-appeal” because the State failed to file its own no*597tice of appeal.2 We granted the State’s petition for review to resolve a split in the courts of appeals on whether the State must file a separate notice of appeal when the defendant appeals his conviction and the State wishes to appeal a ruling of law under Article 44.01(c) of the Texas Code of Criminal Procedure.3 We hold that the State need not file its own notice of appeal when it raises a cross-point concerning a ruling on a question of law under Article 44.01(c).4

I.

At the motion to suppress hearing, Trooper Kuhelengel testified that he stopped appellant because his “dooley” truck5 did not have mud flaps. The trooper noted that appellant seemed nervous and did not give definitive answers to his questions. Trooper Kuhelengel checked appellant’s license through dispatch and found no outstanding warrants. While waiting for that reply from dispatch, Trooper Kuhelengel received a phone call from Investigator Mark Perkins of Red River County. When the State began to offer evidence of what Investigator Perkins told him, defense counsel objected.

Q: All right, and at some point in that time when you were doing that, were you contacted by someone else?

A: I received a call very shortly after I submitted his name and date of birth, I believe it was, and I received a call from Investigator Mark Perkins of Red River County.

Q: And what did Investigator Perkins advise you?

A: Mr. Perkins advised me that ... [Defense Counsel]: Object, Your Hon- or. Hearsay.

Q: Based on what Mr. Perkins advised you, did you have some concern? [Defense Counsel]: Object, Your Hon- or. That’s hearsay. Back door into it.

Q: Not for the truth. As to what his actions are.

[Court]: As to what action he took, the objection will be overruled as the exception.

After the trial judge overruled appellant’s objection, Trooper Kuhelengel summarized the facts that raised his suspicions that appellant might have drugs in his truck: (1) appellant did not give “definite answers on the questions that I ask[ed]”; (2) appellant’s hands shook visibly when he talked; (3) appellant’s voice was “rattling with nervousness”; (4) “and of course the information that I received by telephone.”6 *598The trooper asked appellant if he could search his truck. Appellant said, “No.” Trooper Kuhelengel then called the sheriffs office to see if a canine unit was available. Deputy Hamrick and his dog arrived about ten minutes later. The dog “hit” on the truck and began “serious barking, kind of a frenzy right there at the passenger side of that truek[.]” Based on the dog’s “hit,” the officers began to search the truck. Deputy Hamrick found a pill bottle that contained 7.13 grams of methamphetamine under the front floorboard.

After hearing the evidence, the trial court denied the motion to suppress. Appellant then pled guilty to possession of methamphetamine and was sentenced to ten years’ probation.

On appeal, the Texarkana Court of Appeals reversed the trial court’s order and found that Trooper Kuhelengel “lacked reasonable suspicion to continue detaining Pfeiffer while waiting for a canine unit” because his “request for a canine unit was clearly unrelated to the reason for the stop and exceeded the scope of the initial traffic investigation.”7 The court of appeals noted the call from Investigator Mark Perkins, who “ ‘relayed the information’ that gave him (Kuhelengel) ‘reasonable suspicion that drugs may be in [Pfeiffer’s] vehicle.’ ”8 But it declined to address the State’s cross-issue “complaining that the trial court erred by excluding Kuhelengel’s testimony regarding what Perkins told him” since “the State is required to file a notice of appeal in order to perfect a cross-appeal under Article 44.01 of the Texas Code of Criminal Procedure.”9 Because the State failed to file a notice of appeal, the court found that it “lack[ed] jurisdiction to consider any cross-appeal raised by the State.”10

II.

We granted review to resolve a split in the courts of appeals concerning their jurisdiction to address the State’s “cross-appeal” or “cross-issue.” On one side, the Fourth and Fourteenth Courts of Appeals have held that the State is not required to file a notice of appeal when the defendant appeals his conviction and the State wishes to raise an issue on a ruling of law made by the trial court.11 The Third, Fifth, and Ninth Courts of Appeals, however, have held that the State must file a notice of appeal, even under Article 44.01(c).12

*599A. Jurisdiction of the Courts of Appeals

An appellate court’s jurisdiction is invoked by the timely filing of a notice of appeal.13 Proper notice of appeal vests the appellate courts of this State with a broad scope of review and revision over a criminal case.14 “Once jurisdiction of an appellate court is invoked, exercise of its reviewing functions is limited only by its own discretion or a valid restrictive statute.”15 For example, appellate courts may review unassigned error — a claim that was preserved in the trial court but was not raised by either party on appeal.16 In Carter, we stated, “There is a fundamental proposition pertaining to appellate functions of the Judicial Department: A constitutional grant of appellate jurisdiction treats a right of appeal in criminal cases ‘as a remedy to revise the whole case upon the law and facts, as exhibited in the record[.]’ ”17 Thus, when a defendant appeals his conviction, the courts of appeals have the jurisdiction to address any error in that case. This was true before the State obtained a limited right to appeal in 1987, and it is true today.

More recently, in Mizell v. State,18 we held that, because the defendant appealed his conviction and the appellate court therefore had jurisdiction over the case, the State was not required to file a notice of appeal before it could point out appellant’s illegal sentence to the court of appeals.19 The State could have independently filed a notice of appeal concerning the defendant’s illegal sentence under Article 44.01(b) if the defendant did not himself appeal his conviction. But because the defendant did appeal his conviction, the entire case was subject to review, and the State could raise its claim of an illegal sentence without filing any notice of appeal.20 In sum, a proper notice of appeal in a criminal case confers jurisdiction upon a court of appeals, and that court then has the authority to address any issue or claim pertinent to the judgment or order appealed from unless otherwise restricted by statute.

B. The State’s Right to Appeal

Until 1987, the State had no independent right to appeal from trial court rulings, either pre-trial or post-trial. In 1987, the State obtained a limited right to appeal certain trial-court orders and rulings when the Texas Legislature enacted Article 44.01 of the Texas Code of Criminal Proce*600dure.21 The State’s right to appeal was limited to the specific circumstances set forth in Article 44.01 and only as provided by the procedure set out in the statute.22

First, Article 44.01(a) enumerates the various types of “orders” that the State may appeal. Appealable “orders” under paragraph (a) include various pretrial orders and some post-trial orders.23 Second, Article 44.01(b) provides that the State may appeal an illegal sentence.24 Third, Article 44.01(c) allows the State to appeal a ruling on a question of law if the defendant is convicted and he appeals the judgment. Under paragraph (c), the State has no independent right of appeal—only the defendant can put the ball into play by pursuing an appeal. His notice of appeal confers jurisdiction upon the court of appeals to address any issue or claim pertinent to the judgment or order that the defendant is appealing.

For paragraphs (a) and (b), the State must file a notice of appeal no later than the twentieth day after the court enters an .order, ruling, or sentence.25 Furthermore, the State is entitled to a stay in the proceedings for appeals under paragraphs (a) and (b),26 as well as expedited proceedings for those appeals.27 However, no such requirements apply when the defendant appeals because he has already filed notice of appeal and has thus invoked the broad jurisdiction of an appellate court.28 There is also no “stay” in the trial court proceedings or expedited appeal under paragraph (c) because, when the defendant appeals his conviction, the trial court proceedings have already been completed and the appeal will be accorded its normal priority.

Neither party in this case—and no prior decision by any court of appeals—has cited any legislative history from the 1987 enactment of the State’s right to appeal bill that would suggest that the Texas Legislature sub silentio intended that the State be required to file a notice of appeal in the “cross-appeal” situation. Nor have the parties or any courts of appeals suggested precisely when the State should file such a notice because it has no independent right to appeal in this situation.

C. Purpose of Article 44.01(c)

Article 44.01(c) permits the State to “cross-appeal” a separate ruling of law—though not fact—by the trial judge when the defendant is convicted and ap*601peals his judgment. A “cross-appeal” under 44.01(c) differs from the State’s responsive arguments that relate directly to the defendant’s appellate claims. Responsive issues or points simply rebut the defendant’s claim and assert that the trial judge’s order or judgment should be upheld. A “cross-appeal” asserts that, once the court of appeals has dealt with the defendant’s claim of “X” error, it should, under some circumstances, also address a separate legal ruling by the trial judge— ruling “Y” — that the State claims is erroneous.

The State’s right to cross-appeal is limited, however, as noted in our prior decision in Armstrong v. Stated.29 An appellate court will not address the State’s cross-appeal issue “if the State would not be able to implement a decision in its favor on that issue.”30 Thus, generally speaking, “[i]f the defendant is granted no relief and no retrial will therefore be held, the State will not be able to benefit from a favorable decision on its cross-points of error.”31

Our decision in Armstrong sets forth a bright-line rule that appellate courts should not address the State’s cross-points in such cases32 because this Court and the courts of appeals “are without authority to render advisory opinions.”33 But if the State is “likely to benefit from resolution of its cross-points in its favor,” then the issues raised in the State’s cross-points are “functionally in dispute” and a decision on them is neither advisory nor beyond the jurisdiction or authority of the appellate courts.34

Usually, courts of appeals may address the State’s cross-appeal point only if the defendant prevails on appeal and the case will be remanded for further proceedings. However, in some circumstances, the State might obtain relief even when the defendant does not prevail.35 A cross-appeal concerning an illegal sentence, as in Mi-zett, is one example,36 although the State *602could independently appeal an illegal sentence even if the defendant did not appeal his conviction.

D. Must the State file a notice of appeal before it may raise a cross-appeal issue in the defendant’s appeal?

Paragraph (d) of Article 44.01 explicitly requires the State to file a notice of appeal within 20 days after the trial court’s order, ruling, or sentence if the State is appealing under either Article 44.01(a) or (b). But there is no such statutory requirement when the State raises a cross-appeal under Article 44.01(c). We cannot assume that the Legislature was so inattentive that it simply “forgot” about paragraph (c) when it set out the procedures for the State to file a notice of appeal. And there is no provision for when the State would be required to file such a notice when its right to raise a cross-appeal issue depends entirely upon the defendant timely filing a notice of appeal. Of course the State could not raise cross-appeal issues until after the defendant had appealed because the State has no independent right to appeal under paragraph (c).

What would be the purpose of the State’s filing of a notice of appeal after the defendant has already done so if the court of appeals already had jurisdiction over the case? The courts of appeals have differed on the answer to this question. The Fourth and Fourteenth Courts of Appeals have held that the State is not required to file a notice of appeal when raising a cross-point after the defendant has already appealed. In Mizell, the Fourth Court of Appeals held that the State was not required to file a notice of appeal when appealing a ruling on a question of law under Article 44.01(c) because the notiee-of-appeal provision in Article 44.01(d) is explicitly restricted to paragraphs (a) and (b).37 The court further noted that Rule 25.2 of the Texas Rules of Appellate Procedure, unlike Rule 25.1, does not expressly state “who must file” a notice of appeal in a criminal case.38

Similarly, the Fourteenth Court of Appeals, in McClinton v. State,39 noted that the State sought review of the trial court’s reformation of the sentence after the defendant appealed his conviction.40 That court addressed the merits of the State’s issue, reasoning that, although “[ujnder the civil appellate rules, this court would not be authorized to grant the State relief because the State did not file a notice of appeal.... The criminal analog has no such provision.”41 Because there was no statutory requirement that the State file a *603notice of appeal when the defendant had already invoked the jurisdiction of the appellate court, the court did not judicially create such a requirement.

Conversely, the Third, Fifth, and Ninth Courts of Appeals have held that the State must file a notice of appeal to raise a “cross-appeal” under Article 44.01(c). The Third Court of Appeals, in Ganesan v. State,42 declined to consider excluded testimony offered by the State after the defendant appealed his conviction because the State did not file a notice of appeal.43 In Strong v. State,44 the Fifth Court of Appeals looked to Appellate Rule 25.2(a),45 and held that “[n]o language in either article 44.01 or the appellate rules exempts the State from the notice of appeal requirement under of rule 25.2(a) when it is appealing under article 44.01(c).”46 Therefore, it reasoned, the Texas Legislature’s “failure to impose a time limit in which an appeal must be filed under article 44.01(c) does not support a presumption that no notice of appeal is required at all.”47 In Malley v. State,48 the Beaumont Court of Appeals simply asserted that the State did not file a notice of appeal “as it must in order to perfect an appeal.”49 None of these eases addressed the fact that the court of appeals already had jurisdiction over the entire case because the defendant had been convicted and had appealed the judgment.

As Professors Dix and Schmolesky have noted, the Texas Rules of Appellate Procedure themselves suggest that the State’s cross-appeal is not subject to the requirement of perfection by notice of appeal.50 Rule of Appellate Procedure 26.2 “purports — without qualification — to require the filing of a notice of appeal by the State now within 20 days of the action to be appealed, although the statutory 20-day limit on State appeals is carefully phrased so as not to apply to cross-appeals.”51 Professors Dix and Schmolesky offer an illustrative hypothetical to explain why the State should not be required to file a notice of appeal to raise a “cross-appeal” issue when the defendant has been convicted and appeals: A convicted defendant does not have to give notice of appeal until 30 days after conviction.52 Rule 26.2, therefore, “could not be fairly applied to the State in [a] cross-appeal situation; this would permit a defendant to frustrate the State’s ability [to] cross-appeal by delaying the defendant’s notice of appeal until after the time for filing notice of cross-appeal had expired.”53

In civil cases, under Rule 25.1(c) of the Texas Rules of Appellate Procedure, any party “who seeks to alter the trial court’s *604judgment or other appealable order must file a notice of appeal” and may do so within 14 days after the opposing party files notice of appeal. There is, however, no counterpart to Rule 25.1(c) for criminal cases. And there is no reference in either Article 44.01 or Rule 25.2 to this civil rule. The State does not seek to alter the judgment of conviction or appealable order when the defendant is convicted and appeals,54 so that provision would not be applicable, even by implication, to “cross-appeals” by the State. Usually a “cross-appeal” under Article 44.01(c) seeks contingent relief, not independent relief. In those instances, the State’s position is this: Affirm the trial court’s judgment, but if you are going to reverse the trial court’s judgment, then (and only then) you should address this separate legal ruling because it will arise again when the case returns to the trial court. There will generally be no need to address the State’s “cross-appeal” if the defendant loses his appeal.55 Instead, the appellate court should simply say that it does not need to reach the issue because the State could not implement any ruling in its favor, and the courts of appeals do not render advisory opinions on a moot point.

In sum, we conclude that the State is not required to file a notice of appeal when it raises a “cross-appeal” under Article 44.01(e) because

(1) there is no statutory provision for filing a notice of appeal for “cross-appeals” under Article 44.01(c);

(2) there is no legislative history cited by any court or party suggesting that the Legislature, in implementing the State’s right to appeal in 1987, intended for the State to file a notice of appeal for these “cross-appeals”;

(3) a court of appeals already has broad jurisdiction over the entire case by virtue of the convicted defendant’s notice of appeal;

(4) there is no persuasive rationale for requiring such notice of appeal when the State’s right to have the court of appeals address its issue on a trial court’s ruling of law is contingent upon the defendant obtaining relief from his conviction; and

(5) there is no statutory provision that provides an appropriate time for the State to file a notice of appeal under Article 44.01(c). The State cannot file a notice of appeal within the 20 day limit specified for State-initiated appeals under Article 44.01(a) & (b) because it has no independent right to appeal under paragraph (c), and the defendant has 30 days in which to file his notice of appeal. Tex. R.App. P. 25.1 applies only to civil cases, and, in any event, it would not apply to a “cross-appeal” by the State because the State is not seeking to alter the judgment or other appealable order.

Thus, once a convicted defendant files a timely notice of appeal, the appellate courts have jurisdiction to address any pertinent “cross-appeal” or “rebuttal” issues raised by the State. Procedurally, “cross-appeals” and “rebuttal” issues are treated in the same manner.

*605III.

In the present case, the court of appeals did not address the State’s response to appellant’s claim that Trooper Kuhelengel lacked reasonable suspicion to detain appellant until the canine unit arrived. The purported “cross-appeal” was merely part of the State’s argument on direct appeal as to why the court of appeals should have considered Trooper Kuhelengel’s testimony regarding his call from Investigator Perkins. After its short discussion concerning the admissibility of hearsay to establish reasonable suspicion or probable cause, the State concluded, “This court should so hold, if remanding.”56 The court of appeals erroneously held that it did not have jurisdiction to consider the State’s argument.57

We therefore reverse the court of appeals and remand the case to that court for further proceedings not inconsistent with this opinion.

dissenting.

The majority has determined that the State does not need to file a notice of appeal when it raises a cross-point concerning a ruling on a question of law under Article 44.01(c) of the Texas Code of Criminal Procedure. Maj. op. at 604-05. First of all, this appeal is unfounded because the State did not attempt to cross-appeal the admissibility of certain testimony in the suppression hearing. Rather, the State merely brought up the event to support its argument that Pfeiffer’s detention was supported by some additional reasonable suspicion. The Sixth Court of Appeals unnecessarily stated in a footnote that it did not have jurisdiction to review the State’s cross-appeal since the State did not file a notice of appeal. Pfeiffer v. State, No. 06-11-00001-CR, 2011 WL 1734065, at *4 n. 1 (Tex.App.-Texarkana May 4, 2011). This footnote formed the basis for this review, which should not have been granted. The majority here is as mistaken as the court of appeals was, by characterizing the State’s argument as a cross-appeal.

With Article 44.01, the legislature developed very specific rules that the State must follow in order to appeal. See Mizell v. State, 119 S.W.3d 804, 806-07 (Tex.Crim.App. 2003). Article 44.01(c) allows the State to appeal after a defendant has appealed, since the defendant’s appeal will often occur after the twenty days allowed for the State’s appeal under Rule 26.2(b) have passed. The majority argues that the timing of the appeals under Rule 26.2 would allow the defendant to frustrate the State’s ability to file a cross-appeal, thus, Article 44.01(c) could not require the State to file a cross-appeal. Maj. op. at 603. I disagree. Nothing in Article 44.01 indicates that the State does not have to file notice of a cross-appeal.

The State’s brief to the court of appeals was hardly a notice of appeal, it was merely part of the argument as to why the officer’s detention of the defendant was reasonable.1 Nevertheless, the majority *606analyzes the argument as a cross-appeal and implies that an appellate court has jurisdiction over matters raised for appeal by the State, simply because the defendant has appealed. Maj. op. at 604-05. It is true that appellate courts have jurisdiction over the parties once the defendant appeals, but the court has subject matter jurisdiction over only the issues raised by the defendant. The State must file notice of appeal in order for its points of error to become subject to the jurisdiction of the appellate court. I have to agree with the Texarkana Court of Appeals here, since the court properly held that it did not have jurisdiction to consider the merits of the State’s “appeal.”

This is a fairly significant opinion because it creates jurisdiction merely by the opposing party mentioning their counterargument in its reply brief. I presume this right is now extended to defendants. But, the majority’s holding here has prejudiced the defendant because she did not know that the State intended to appeal until the State’s reply brief was filed. A defendant should always have adequate notice of an appeal and then have the opportunity to reply to a fully briefed cross-appeal.

In conclusion, I first of all do not believe that this was a cross-appeal by the State since it was only a small portion of the State’s brief and the State did not seem to intend to file an appeal. However, since we granted review, I believe that the majority improperly interprets Article 44.01(c) in determining that the State does not have to file a notice of appeal if the defendant appeals. The holding is incorrect because the court of appeals did not have subject matter jurisdiction over the issues raised by the State unless or until the State directly appealed the challenged matters. Therefore, I respectfully dissent.